I would try removing the glue from it. Enermaxes of that era were known to use a type of glue that turns conductive.

PcBytes wrote on 2024-09-07, 18:17:

I would try removing the glue from it. Enermaxes of that era were known to use a type of glue that turns conductive.

I have yet to open it. I'll wait several hours to be sure that any residual power is gone and, tomorrow, I'll take a look into it. If there's glue, I'll try removing it.
Just: Any suggestion on how to remove hot glue from electronics component? I've only done that with glue so dry and old that it came off on it's own, without force.

Mondodimotori wrote on 2024-09-07, 18:26:

I have yet to open it. I'll wait several hours to be sure that any residual power is gone and, tomorrow, I'll take a look into it. If there's glue, I'll try removing it.
Just: Any suggestion on how to remove hot glue from electronics component? I've only done that with glue so dry and old that it came off on it's own, without force.

They say that standard consumer hot glue is easily removed using isopropyl alcohol. Isopropyl alcohol is a standard solvent for PCB cleaning, so you shouldn't need to worry about collateral damage. Don't use acetone (might be contained in nail polish remover) as "substitute" if you don't have isopropyl alcohol at hand. That solvent will most likely weaken / loosen the glue as well, but it will likely also dissolve stuff you don't want to get dissolved.

mkarcher wrote on 2024-09-07, 18:47:

They say that standard consumer hot glue is easily removed using isopropyl alcohol. Isopropyl alcohol is a standard solvent for PCB cleaning, so you shouldn't need to worry about collateral damage. Don't use acetone (might be contained in nail polish remover) as "substitute" if you don't have isopropyl alcohol at hand. That solvent will most likely weaken / loosen the glue as well, but it will likely also dissolve stuff you don't want to get dissolved.

Oh yeah! I've alredy got it, after all I'm into DIY PC building and used it several times when removing thermal paste and the like, but didn't know it was effective even on hot glue.
I'll try that and see if the whine goes away. I would love for it to be the case, since recappig is a skill I have yet to acquire, and I would need some time to be effective at it.

Thanks for the input!

Mondodimotori wrote on 2024-09-07, 17:48:

Just got an used Enermax EG495AX-VE(W) to use either in a socket A or socket 370 build (Currently in the socket A with Athlon 14 […]
Show full quote

Just got an used Enermax EG495AX-VE(W) to use either in a socket A or socket 370 build (Currently in the socket A with Athlon 1400C, where high voltages on 5V are needed).

And, just as said in the title, it produces a very high pitch whine when connected to the power, with the PC still of. As I turn on the PC, the whine disappears and the PC boots normally. It runs fine, even during games and 3dmark99. When i power it off, the whine doens't return, but the PSU fans still spins (I've read it's a feature of this model to keep cooling the PSU even after power off). But if I disconnect the power, wait for the fans to stop spinning, and then reconnect the power, the whine is there again.

I have the suspicion it may be a capacitor (or maybe more than one) on it's way to PC heaven, maybe one of those responsible of keeping those fans spinning after power off. I've read that Enermax PSUs are the among the most reliable from that period of time, and both the original PSUs of those builds (cheap, unknown brand and 250W) works fine without any strange noises. but still wanted to share and gather opinions from people much more expert than me.

PS: In that same socket A build I've also used a new PSU with 25 amp on the 5V, but under heavy load Everest reported it dropping to 4.66V, apparently pretty close to full sistem shutdown. I'll make a full report in the thread I have opened a few weeks ago, the one about cooling an Athlon 1400C.

Hello my friend, I have some power supplies from various quality brands, including Enermax, one of the best, it has the function of continuing to spin the fans, when the PC is turned off, and they continue to spin for a while, I don't know exactly if one or two minutes, however this is normal.
As for the problem with your power supply, a visual inspection could highlight no problem, first you should understand where it comes from, from what I remember it could be a problem, not due to an electronic defect, but a mechanical one, if it came from the transformer, and I say if, there could be the part that connects the two windings that has a backlash, and in certain conditions it vibrates, and generates an annoying sound.
Keep in mind that I don't recommend opening it, at most you could try shaking it and if you hear a clack, it's clear that there's something moving, and that's probably where the problem is.

PC@LIVE wrote on 2024-09-07, 21:44:

Hello my friend, I have some power supplies from various quality brands, including Enermax, one of the best, it has the function […]
Show full quote

Mondodimotori wrote on 2024-09-07, 17:48:

Just got an used Enermax EG495AX-VE(W) to use either in a socket A or socket 370 build (Currently in the socket A with Athlon 14 […]
Show full quote

Just got an used Enermax EG495AX-VE(W) to use either in a socket A or socket 370 build (Currently in the socket A with Athlon 1400C, where high voltages on 5V are needed).

And, just as said in the title, it produces a very high pitch whine when connected to the power, with the PC still of. As I turn on the PC, the whine disappears and the PC boots normally. It runs fine, even during games and 3dmark99. When i power it off, the whine doens't return, but the PSU fans still spins (I've read it's a feature of this model to keep cooling the PSU even after power off). But if I disconnect the power, wait for the fans to stop spinning, and then reconnect the power, the whine is there again.

I have the suspicion it may be a capacitor (or maybe more than one) on it's way to PC heaven, maybe one of those responsible of keeping those fans spinning after power off. I've read that Enermax PSUs are the among the most reliable from that period of time, and both the original PSUs of those builds (cheap, unknown brand and 250W) works fine without any strange noises. but still wanted to share and gather opinions from people much more expert than me.

PS: In that same socket A build I've also used a new PSU with 25 amp on the 5V, but under heavy load Everest reported it dropping to 4.66V, apparently pretty close to full sistem shutdown. I'll make a full report in the thread I have opened a few weeks ago, the one about cooling an Athlon 1400C.

Hello my friend, I have some power supplies from various quality brands, including Enermax, one of the best, it has the function of continuing to spin the fans, when the PC is turned off, and they continue to spin for a while, I don't know exactly if one or two minutes, however this is normal.
As for the problem with your power supply, a visual inspection could highlight no problem, first you should understand where it comes from, from what I remember it could be a problem, not due to an electronic defect, but a mechanical one, if it came from the transformer, and I say if, there could be the part that connects the two windings that has a backlash, and in certain conditions it vibrates, and generates an annoying sound.
Keep in mind that I don't recommend opening it, at most you could try shaking it and if you hear a clack, it's clear that there's something moving, and that's probably where the problem is.

Yeah, the fact is that the wine is not vibrating, like coil wine. Is a very high pitch noisem, so high pitch that's even hard to pinpoint where it's coming from, like when your ear start ringing. Or like those dog whistle used in training. I know it comes from the PSU becase the second I put my hand to cover the rear exaust, the noise reduces, like I'm blocking it. Probably, if I put the PC where it's supposed to be, under the desk, the noise would basically be inaudible.

I know the risks of opening a PSU, especially when you're no expert in it, I've lurked this forum for years before posting somethin, but I've also read on this forum that recapping older PSUs is one of the best way to ensure long, reliable life from them. Even when old capacitors don't have any evident sign of wear.

I'll sure take into accout your suggestion, and if tomorrow I get to removing the PSU from the PC, I'll try to give it a shake and hear what's what.

Post a picture (or a few) of the PSU with the top off once you open it tomorrow (today, now that it's early AM hours here? 😁 )

If the PSU has hot glue (which it probably won't, as I don't recall Enermax or any of the better-known PSU manufacturers to use for holding down components), then there's no need to remove it. Hot glue doesn't go conductive like the organic tan glue does. Only the organic tan glue (turns brown/black when its exposed to high heat over time, and that's when it becomes conductive) needs to be removed. Silicone can also stay. IIRC, Enermax used both throughout the years. A picture should be telling enough, though.

As for the whine... yes, it may be a cap or two - probably on the 5VSB output, as that's the only supply that's On when the PSU is in soft-off mode (connected to AC power but PC not turned On.) The reason the whine may stop with the PC On is because once the main PS (5V, 12V rails, and etc.) starts inside the PSU, any load on the 5VSB from the motherboard is often relieved and thrown onto the 5V and 12V rail. Thus, with less load on the 5VSB output, the 5VSB circuit stabilizes and doesn't whine anymore.
Of course, the whine could also be normal too. I have a few PSUs and also an LCD monitor that whines quite A LOT when it's turned "Off". For these, it's simply the standby supply "pulse-skipping" or working at an alternate frequency due to a lower/different load. So a whine may not necessarily be detrimental.

With that said, one tip I'll give you is to never blindly plug-in an old PSU into a motherboard. First always plug it in AC power without a motherboard attached and measure the 5VSB output voltage with a multimeter. If all is well and 5VSB is reasonably close to 5V (I usually expect 4.95 to 5.15V), then next step is to load the 5VSB with a slight load. For this, a 12V 20W incandescent or halogen lamp will do. Connect that between 5VSB and ground and measure the output voltage of the 5VSB rail again. If the 5VSB is still relatively close to 5V (OK to see it drop 0.1 to 0.2V), you're in business. If not, open the PSU and check if for bad caps.
Actually, it's always a good idea to open any used ATX PSU you get and check it for bad caps. There's always the possibility the 5VSB supply (and caps) could be good, and something else bad. So just get in the habit of voiding the (expired) warranty. 😉 If it doubt, post pictures online.
Opening an ATX PSU is safe for the most part, if you take the following precautions:
- Always disconnect / unplug the AC power cord before opening the PSU (or any electronic device for that matter)
- Keep fingers away from internal components, especially from the heatsink(s) on the primary side (the high-voltage side that is not isolated from AC power.)
- Measure DC voltage across primary cap(s) (or bridge rectifier if easier to get at) with a multimeter to make sure they are discharged. Generally, though, if dealing with an ATX PSU that has 2x 200V -rated caps and a voltage-selector switch, then chances are that it will not have an APFC circuit and those caps will usually have bleeder resistors that typically discharge the caps within seconds of removing AC power from the PSU. But if you see a PSU with a 400/420/450V primary cap(s), beware, as those sometimes don't have bleeder resistors and may hold charge for days or even weeks. If dealing with one of those PSUs, you can still open it and work on it, but just avoid touching primary-side components that may have direct connection to the primary cap's terminals.

Enermax PSUs used to have a problem with their power up current limiter. IIRC that was a bigger pear or disk part (green?). The problem got some renown, cause it ended with a flash and a bang. Sometimes this part already looks degraded.

PC@LIVE wrote on 2024-09-07, 21:44:

at most you could try shaking it and if you hear a clack, it's clear that there's something moving, and that's probably where the problem is.

Shook it when unmounted from the sistem. Nothing moves or rattles inside, but the noise seems reduced now (or maybe being it outside the case is resonating less?). But I ended up opening it for taking pictures as requested by another user.

momaka wrote on 2024-09-07, 23:56:

Post a picture (or a few) of the PSU with the top off once you open it tomorrow (today, now that it's early AM hours here? :D ) […]
Show full quote

Post a picture (or a few) of the PSU with the top off once you open it tomorrow (today, now that it's early AM hours here? 😁 )

If the PSU has hot glue (which it probably won't, as I don't recall Enermax or any of the better-known PSU manufacturers to use for holding down components), then there's no need to remove it. Hot glue doesn't go conductive like the organic tan glue does. Only the organic tan glue (turns brown/black when its exposed to high heat over time, and that's when it becomes conductive) needs to be removed. Silicone can also stay. IIRC, Enermax used both throughout the years. A picture should be telling enough, though.

As for the whine... yes, it may be a cap or two - probably on the 5VSB output, as that's the only supply that's On when the PSU is in soft-off mode (connected to AC power but PC not turned On.) The reason the whine may stop with the PC On is because once the main PS (5V, 12V rails, and etc.) starts inside the PSU, any load on the 5VSB from the motherboard is often relieved and thrown onto the 5V and 12V rail. Thus, with less load on the 5VSB output, the 5VSB circuit stabilizes and doesn't whine anymore.
Of course, the whine could also be normal too. I have a few PSUs and also an LCD monitor that whines quite A LOT when it's turned "Off". For these, it's simply the standby supply "pulse-skipping" or working at an alternate frequency due to a lower/different load. So a whine may not necessarily be detrimental.

With that said, one tip I'll give you is to never blindly plug-in an old PSU into a motherboard. First always plug it in AC power without a motherboard attached and measure the 5VSB output voltage with a multimeter. If all is well and 5VSB is reasonably close to 5V (I usually expect 4.95 to 5.15V), then next step is to load the 5VSB with a slight load. For this, a 12V 20W incandescent or halogen lamp will do. Connect that between 5VSB and ground and measure the output voltage of the 5VSB rail again. If the 5VSB is still relatively close to 5V (OK to see it drop 0.1 to 0.2V), you're in business. If not, open the PSU and check if for bad caps.
Actually, it's always a good idea to open any used ATX PSU you get and check it for bad caps. There's always the possibility the 5VSB supply (and caps) could be good, and something else bad. So just get in the habit of voiding the (expired) warranty. 😉 If it doubt, post pictures online.
Opening an ATX PSU is safe for the most part, if you take the following precautions:
- Always disconnect / unplug the AC power cord before opening the PSU (or any electronic device for that matter)
- Keep fingers away from internal components, especially from the heatsink(s) on the primary side (the high-voltage side that is not isolated from AC power.)
- Measure DC voltage across primary cap(s) (or bridge rectifier if easier to get at) with a multimeter to make sure they are discharged. Generally, though, if dealing with an ATX PSU that has 2x 200V -rated caps and a voltage-selector switch, then chances are that it will not have an APFC circuit and those caps will usually have bleeder resistors that typically discharge the caps within seconds of removing AC power from the PSU. But if you see a PSU with a 400/420/450V primary cap(s), beware, as those sometimes don't have bleeder resistors and may hold charge for days or even weeks. If dealing with one of those PSUs, you can still open it and work on it, but just avoid touching primary-side components that may have direct connection to the primary cap's terminals.

I'm in Europe too, so I don't think our time zones are that far apart. Anyway, here's the photos of the inside, I've also took a video (the Drive link) where, if you have decent speakers or headphones, you can hear the whine. It actually goes up in pitch when you disconnect power untill it disappear. Performed these new test with the PSU outside and disconnected from the sistem. But overall all the capacitors seems in good conditions: No bulgind and absolutely no leaking.

Under spoiler the video and five of the pictures I've took. If more are needed, I'll provide, the PSU is still outside the sistem and readily available. I've made sure to disconnect it and not touch anything inside. Just looking.

Spoiler

https://drive.google.com/file/d/14JCYrf59Wb-S … iew?usp=sharing

As for the suggestion when getting a "new" used PSU, I'll get all the equipment in case I'll do this again. But, honestly, I don't think I'm gonna build a third sistem from this time period. The next one will be a late XP era sistem, or as a I call it "the sistem I wish I had in 2008 to replace the socket A I had", so a modern power supply from reputable brand should be more than enough.

ux-3 wrote on 2024-09-08, 06:20:

Enermax PSUs used to have a problem with their power up current limiter. IIRC that was a bigger pear or disk part (green?). The problem got some renown, cause it ended with a flash and a bang. Sometimes this part already looks degraded.

So... It also may be the case to get protective glasses and a fire extinguisher ready...?

It is little bit difficult to make out details from the photos as the PCB is in the case, but the caps shown in the photos visually seem fine, although that doesn't tell the whole story. I also think that the whine may be caused by the 5Vsb line as that is the one that has current always when the PSU switch is on and it is plugged to an outlet.

Mondodimotori wrote on 2024-09-08, 15:03:

As for the suggestion when getting a "new" used PSU, I'll get all the equipment in case I'll do this again. But, honestly, I don't think I'm gonna build a third sistem from this time period. The next one will be a late XP era sistem, or as a I call it "the sistem I wish I had in 2008 to replace the socket A I had", so a modern power supply from reputable brand should be more than enough.

Socket A systems are pretty cool IMO, so as you pretty much have bunch of parts already, one option for you could be getting a socket A motherboard which has a 12V VRM, if you don't want to hassle with these old PSUs. Having a motherboard with 12V CPU VRM makes it much easier to use modern PSUs without any problems. High end Thunderbird with a MB using 5V CPU VRM is pretty much as challenging as it gets as far as the 5V load is concerned and modern PSUs, especially group regulated ones, can't handle them unless they are something like top of the line extremely powerful quality models. And IMO there is not much point putting something like that in systems like these. That's why I don't usually recommend Socket A as a first retro computer build to anyone without reservations and these considerations. It may just lead to a frustration.

Edit: I forgot to add that the other hurdle with Socket A is that motherboards from the era are from the period of worst ”capacitor plague” as manufacturers used cheap chinese ultra low esr caps on VRM, which went bad after a year or two. Many MBs absolutely require recapping on VRM at least, and those multilayer PCBs aren’t something that should be the first repair project.

CharlieFoxtrot wrote on 2024-09-08, 17:24:

It is little bit difficult to make out details from the photos as the PCB is in the case, but the caps shown in the photos visually seem fine, although that doesn't tell the whole story. I also think that the whine may be caused by the 5Vsb line as that is the one that has current always when the PSU switch is on and it is plugged to an outlet.

So, what are my option in this case? Just ignore it and unplug it when the PC is not in use? Or could it be an issue that could escalate in bigger problems down the line? I mean, I could still put the new PSU in it, even if it drops to 4.66V under load. As long as it doesn't shut down on me and it's stable, I'm fine. If better pictures are needed, I can provide those.

CharlieFoxtrot wrote on 2024-09-08, 17:24:

Socket A systems are pretty cool IMO, so as you pretty much have bunch of parts already, one option for you could be getting a socket A motherboard which has a 12V VRM, if you don't want to hassle with these old PSUs. Having a motherboard with 12V CPU VRM makes it much easier to use modern PSUs without any problems. High end Thunderbird with a MB using 5V CPU VRM is pretty much as challenging as it gets as far as the 5V load is concerned and modern PSUs, especially group regulated ones, can't handle them unless they are something like top of the line extremely powerful quality models. And IMO there is not much point putting something like that in systems like these. That's why I don't usually recommend Socket A as a first retro computer build to anyone without reservations and these considerations. It may just lead to a frustration.

Edit: I forgot to add that the other hurdle with Socket A is that motherboards from the era are from the period of worst ”capacitor plague” as manufacturers used cheap chinese ultra low esr caps on VRM, which went bad after a year or two. Many MBs absolutely require recapping on VRM at least, and those multilayer PCBs aren’t something that should be the first repair project.

The fact is: This is my first PC that I got back in 2001. I recovered it after 15 years in storage and I wanted to have it running without spending to much. All I wanted was to replace CPU (it wasn't actually planned, I did it because the Duron 1.1 it had was limited in lot's of gaming scenarios), power supply (just because I didn't trust of the 23 years old one) and finally add a dedicated GPU in the only available PCI slots (this mobo has no AGP slot). I didn't plan to build it from scratch, otherwise I would've gone with a late Athlon XP and an AGP slot, so to create a "definitive" windows 9x machine.

The problem with modern PSUs is: Every site I went from reputable manufacturers (cooler master, seasonic, corsair... you name it) , I couldn't find anymore any PSU that had decent amperage on the 3.3 and 5V rail. Even top of the range 1000+ Watts PSUs have little over 20 amps there and 140/150W of combined power.
I've lurked this forum a lot before posting, and all those "modern" PSUs from threads not even 4 years old are out of stock and no more into production. Everyone has moved to the 12V rail.
True, the one I got is not from a reputable brand (even if reviews online don't complain about it), and it was actually manufactured in 2020, by the sticker on it. But it has 25 amp on the 5V, and a maximum combined power delivery of 195 watts. And the sistem did ran stable. And it's for sure safer than an used PSU with unknown history
Of course, I didn't want to overstress it (and will end up in the 370 build), and that's why I got that Enermax. I didn't pay much for it and it was pulled from a working sistem several years ago (maybe a pentium 4 sistem, the seller wasn't a PC expert), and I was able to source it locally, so that I could see it and talk with the seller.
So, as long as it's not unsafe to run, even with the whine, I can make it work with it. And when I learn to recap, I'll recap both the PSU and the MOBO.
That's what I'm looking for with the PSU: a piece that run stable and the least possible chance of frying the MOBO. That new PSU was doing it, even if barely (didn't experience any instability, but I don't know how close it actually was). This Enermax is doing that too, whine aside.

EDIT: Here's an idea that went thorugh my mind recently: What about industrial power supply? Let's ignore the price for now (yikes), and let's look at the datasheet for this one: https://www.bicker.de/files/downloads/datenbl … t/bea-635_e.pdf
Just a waste of time and money to look into these, or there could be something here?

I've done a re-cap of an Enermax of that era. Capacitors are CEC brand (I believe "TUR" series)... Replace the capacitors.

mockingbird wrote on 2024-09-08, 22:05:

I've done a re-cap of an Enermax of that era. Capacitors are CEC brand (I believe "TUR" series)... Replace the capacitors.

I have recapped three vintage Enermax PSUs. Although mine are a bit older than the one OP has, yes they all had CEC caps. Most smaller capacitance caps are TUR, but the larger have been TUL series, which I believe was the low esr and TUR was the general use series.

Mondodimotori wrote on 2024-09-08, 19:56:

So, what are my option in this case? Just ignore it and unplug it when the PC is not in use? Or could it be an issue that could escalate in bigger problems down the line? I mean, I could still put the new PSU in it, even if it drops to 4.66V under load. As long as it doesn't shut down on me and it's stable, I'm fine. If better pictures are needed, I can provide those.

I wouldn't use old PSU that doesn't work as it supposed to and especially if you haven't properly measured the outputs and you haven't actually isolated what is wrong with it. If that 5Vsb line is out of spec (too much) it will possibly break something on your MB as it is ALWAYS on, also when the computer is running. So you can't avoid it.

Your newer PSU is most likely group regulated PSU and mainly designed to be used with 12V heavy systems. It can't cope with a significant crossload outside of its main design parameters and that is the reason why your 5V line tanks. This very typical for cheap group regulated PSUs when the lines experience "abnormal" load.

I wouldn't put my bets on that newer PSU either, because it seems to be woefully inadequate for your system. It may not be that big of a risk for the components, but then again it is clearly struggling and may give up the ghost as well. And that 4.66V is so much under the 5V spec that I wouldn't trust that the system is actually stable.

The fact is: This is my first PC that I got back in 2001. I recovered it after 15 years in storage and I wanted to have it runni […]
Show full quote

The fact is: This is my first PC that I got back in 2001. I recovered it after 15 years in storage and I wanted to have it running without spending to much. All I wanted was to replace CPU (it wasn't actually planned, I did it because the Duron 1.1 it had was limited in lot's of gaming scenarios), power supply (just because I didn't trust of the 23 years old one) and finally add a dedicated GPU in the only available PCI slots (this mobo has no AGP slot). I didn't plan to build it from scratch, otherwise I would've gone with a late Athlon XP and an AGP slot, so to create a "definitive" windows 9x machine.

The problem with modern PSUs is: Every site I went from reputable manufacturers (cooler master, seasonic, corsair... you name it) , I couldn't find anymore any PSU that had decent amperage on the 3.3 and 5V rail. Even top of the range 1000+ Watts PSUs have little over 20 amps there and 140/150W of combined power.
I've lurked this forum a lot before posting, and all those "modern" PSUs from threads not even 4 years old are out of stock and no more into production. Everyone has moved to the 12V rail.
True, the one I got is not from a reputable brand (even if reviews online don't complain about it), and it was actually manufactured in 2020, by the sticker on it. But it has 25 amp on the 5V, and a maximum combined power delivery of 195 watts. And the sistem did ran stable. And it's for sure safer than an used PSU with unknown history
Of course, I didn't want to overstress it (and will end up in the 370 build), and that's why I got that Enermax. I didn't pay much for it and it was pulled from a working sistem several years ago (maybe a pentium 4 sistem, the seller wasn't a PC expert), and I was able to source it locally, so that I could see it and talk with the seller.
So, as long as it's not unsafe to run, even with the whine, I can make it work with it. And when I learn to recap, I'll recap both the PSU and the MOBO.
That's what I'm looking for with the PSU: a piece that run stable and the least possible chance of frying the MOBO. That new PSU was doing it, even if barely (didn't experience any instability, but I don't know how close it actually was). This Enermax is doing that too, whine aside.

EDIT: Here's an idea that went thorugh my mind recently: What about industrial power supply? Let's ignore the price for now (yikes), and let's look at the datasheet for this one: https://www.bicker.de/files/downloads/datenbl … t/bea-635_e.pdf
Just a waste of time and money to look into these, or there could be something here?

Completely understandable that you want to start using what you already have. That is the way to start the hobby. The point is that if you would get a working mobo with 12V VRM, you could utilize everything elese you have and then perhaps at some point upgrade to beefier Athlon XP, better GPUs more on the line of such system and so on. But with Socket A and MB with 5V VRM you have undeniably a power problem that you need to solve somehow. And this is the exact reason why I said that I don't recommend Socket A based systems as a starting point for the hobby without serious considerations. With socket A in general, you have one or both potential issues at your hand depending on what parts you have: failed capacitors on motherboard and finding a working and reliable PSU. Neither is an issue, if you are able to fix old parts, but that is not perhaps something that should be tackled in the first project.

You are absolutely correct that it gets increasingly more difficult to find a PSU that can deliver close to 25A or more on the 5V or 3.3V lines. It is a while when I checked modern PSUs from this point of view, but at that time I did, I remember that Corsair had some ~1,5kW supplies that could deliver 25-30A. I don't find it meaningful to install such PSU worth of hundreds of euros/equivalent on a low cost retro computer. And some of those PSUs may be so large length-wise that they may not fit with some vintaage cases to begin with.

I don't see a reason why such industrial PSU wouldn't work. The problem with these is that they may be either difficult or impossible to source for consumers or then they are at least really expensive. Is it worth it? I think it is about personal preference. For me? Absolutely not, I just recap a vintage PSU, measure it so that it is in the spec and it should work just fine for a long time taking into consideration the hours these vintage computers will get from me. For someone else it may be different and worth the shot. This is a hobby and like in many other hobbies, there are different preferences and ways to achieve the same goals.

QUESTION: where would I need to look to find the electrical diagram of this PSU?

CharlieFoxtrot wrote on 2024-09-09, 10:10:

I wouldn't use old PSU that doesn't work as it supposed to and especially if you haven't properly measured the outputs and you haven't actually isolated what is wrong with it. If that 5Vsb line is out of spec (too much) it will possibly break something on your MB as it is ALWAYS on, also when the computer is running. So you can't avoid it.

Your newer PSU is most likely group regulated PSU and mainly designed to be used with 12V heavy systems. It can't cope with a significant crossload outside of its main design parameters and that is the reason why your 5V line tanks. This very typical for cheap group regulated PSUs when the lines experience "abnormal" load.

I wouldn't put my bets on that newer PSU either, because it seems to be woefully inadequate for your system. It may not be that big of a risk for the components, but then again it is clearly struggling and may give up the ghost as well. And that 4.66V is so much under the 5V spec that I wouldn't trust that the system is actually stable.

Yeah, maybe I can get a multimeter and see if anything is out of spec. If everything seems normal, I may keep running the PSU. For the new one, I dind't perform hard CPU stress test, like prime 95, but only 3D gaming and benchmark stress test, where the rail would drop to a sensor reported 4.66 (not read with mulitimeter) but the benchmarke kept running without issues for more than an hour. Of course, it may also be bad readings from the sensor, wouldn't be the firt time I encouter this (on the 370 mobo, the CPU temp sensor must be fucked because it always report 51°. No matter if immediately at boot or after hours of intense use. Ant it's a Celeron 700 with a decent cooler in it! With the case remaining nice and cool to the touch).
So I'm still thinking of resolving the issue with this Enermax and using it in the Socket A build, and move the other one in the 370 build.
I may also take a look around if I can find a Socket A mobo with a 12 volt input for the CPU at a decent price (meaning less than reparing/getting an ew PSU)

CharlieFoxtrot wrote on 2024-09-09, 10:10:

Completely understandable that you want to start using what you already have. That is the way to start the hobby. The point is that if you would get a working mobo with 12V VRM, you could utilize everything elese you have and then perhaps at some point upgrade to beefier Athlon XP, better GPUs more on the line of such system and so on. But with Socket A and MB with 5V VRM you have undeniably a power problem that you need to solve somehow. And this is the exact reason why I said that I don't recommend Socket A based systems as a starting point for the hobby without serious considerations. With socket A in general, you have one or both potential issues at your hand depending on what parts you have: failed capacitors on motherboard and finding a working and reliable PSU. Neither is an issue, if you are able to fix old parts, but that is not perhaps something that should be tackled in the first project.

You are absolutely correct that it gets increasingly more difficult to find a PSU that can deliver close to 25A or more on the 5V or 3.3V lines. It is a while when I checked modern PSUs from this point of view, but at that time I did, I remember that Corsair had some ~1,5kW supplies that could deliver 25-30A. I don't find it meaningful to install such PSU worth of hundreds of euros/equivalent on a low cost retro computer. And some of those PSUs may be so large length-wise that they may not fit with some vintaage cases to begin with.

I don't see a reason why such industrial PSU wouldn't work. The problem with these is that they may be either difficult or impossible to source for consumers or then they are at least really expensive. Is it worth it? I think it is about personal preference. For me? Absolutely not, I just recap a vintage PSU, measure it so that it is in the spec and it should work just fine for a long time taking into consideration the hours these vintage computers will get from me. For someone else it may be different and worth the shot. This is a hobby and like in many other hobbies, there are different preferences and ways to achieve the same goals.

Yeah, unfortunately I went and check even those top of the line 1000+ watt PSUs from reputable brands: All of them don't go over 20 amp on the 5V and 150 watts combined anymore (unless I find used units from a few years ago), aqnd even from those I've read that you could drop to under 4.75V on the 5V rail when overusing it comparet to the 12V. Wich may be enough If i don't put a faster GPU in there (probably wont) but, maybe, I could go over it if I add anything else, like a sound card.
And yes, industrial ATX PSUs may still be found with decent values on the 3.3 and 5V rail, but of course those are built like actual tanks, and you pay for that build quality (seen some models going between 150 and 300€. Yikes indeed).
At that point it may be cheaper to even having the PSU recapped by a professional.

CharlieFoxtrot wrote on 2024-09-09, 10:10:

You are absolutely correct that it gets increasingly more difficult to find a PSU that can deliver close to 25A or more on the 5V or 3.3V lines. It is a while when I checked modern PSUs from this point of view, but at that time I did, I remember that Corsair had some ~1,5kW supplies that could deliver 25-30A. I don't find it meaningful to install such PSU worth of hundreds of euros/equivalent on a low cost retro computer. And some of those PSUs may be so large length-wise that they may not fit with some vintaage cases to begin with.

i picked up a psu for a family member from my local computer shop it was cheap and a brand i'd never heard of, usually i'd avoid these but since the shops reputable and i've been getting my pc parts there from the late 90's, it wasnt bound to be any old shit. anyway it seems to meet the requirements you're looking for.

Brand: Arctic Blue+
Model: AD-E750AE-A5/A6

Power Output Specifications
+3.3V Rail 24A (170W)
+5V Rail 30A (170W)
+12V1 Rail 32A (729W)
+12V2 Rail 32A (729W)
+12V3 Rail 32A (729W)
+12V4 Rail 32A (729W)
+5Vsb Rail 3.0A (15W)
-12V Rail 0.5A (6W)
Total Power Output 750W

Heres the link:

https://www.novatech.co.uk/products/novatech- … ly/psu-710.html

check the Specs tab.

they also do an 850W, only downside, since brexit they dont ship outside the uk, they've got one on amazon but the box is different so dont know if its the same model.

DudeFace wrote on 2024-09-09, 14:07:

I picked up a psu for a family member from my local computer shop it was cheap and a brand i'd never heard of, usually i'd avoid […]
Show full quote

I picked up a psu for a family member from my local computer shop it was cheap and a brand i'd never heard of, usually i'd avoid these but since the shops reputable and i've been getting my pc parts there from the late 90's, it wasnt bound to be any old shit. anyway it seems to meet the requirements you're looking for.

Brand: Arctic Blue+
Model: AD-E750AE-A5/A6

Power Output Specifications
+3.3V Rail 24A (170W)
+5V Rail 30A (170W)
+12V1 Rail 32A (729W)
+12V2 Rail 32A (729W)
+12V3 Rail 32A (729W)
+12V4 Rail 32A (729W)
+5Vsb Rail 3.0A (15W)
-12V Rail 0.5A (6W)
Total Power Output 750W

Heres the link:

https://www.novatech.co.uk/products/novatech- … ly/psu-710.html

check the Specs tab.

they also do an 850W, only downside, since brexit they dont ship outside the uk, they've got one on amazon but the box is different so dont know if its the same model.

Well... I've alredy done that. I've got myself a PSU from a local store, and when the dude at the store heard that I was working on a socket A build, we went on a hour long reminiscence journey. He's older than me and was really into DIY back in those days.
Anyway, he had this HKC for 60 bucks with these specs (pictures under spoiler), and the sistem runs fine. At least it seems: because when checking the sensors with everest, I noticed that under benchmark stress the 5V rail drops to 4.66V. Now, the sistem still goes no problems, but it's should be extremely close to instability and sistem shut down.
Of course he told me "come back to me and tell me if it works", also told me that he used this PSU in other contemporary builds without isses. But what am I supposed to do currently? "Sorry. the sistem runs fine and looks stable, but the mobo sensors tells me that it drops ro 4.66V on the 5V rail"? Maybe, he may even take it back. But since I alredy have it, I can use it with the 370 build, wich doens't stress the 5V rail that much, and infact keeps the 5V rail to 4.9 even under decompression load.

So yeah, Maybe these modern units from unknown brands can deliver those amperage only when you also put some stress on the main 12V line. But if you use almost exclusively the 5V rail, they drop voltage. And since I've got an Athlon classic 1400 in there now, he's gonna suck up that 5V rail like- I don't think it's appropriate to use the metaphore I was going with.

I'll still check if I can find one from a store that ships to italy and accept returns if the item isn't as advertised. Amazon would be great, since they are less prone to protest returns.

Spoiler

Mondodimotori wrote on 2024-09-09, 14:21:

I'll still check if I can find one from a store that ships to italy and accept returns if the item isn't as advertised. Amazon would be great, since they are less prone to protest returns.

i only picked that one up as the shop is reputable and they've sold a lot of that model, if i'd seen it on amazon or ebay i would have passed on it being an unknown brand, i think the one you picked up from a local shop was the best call at least if its not up to the job you can always return it, just becareful buying unknown brands from amazon or ebay, my dad bought one from amazon, an unknown brand which looked nice and had braided cables, turned out to be some cheap shit from china, it was light as a feather like there was nothing inside it, i've had cheap known brand psu's that seemed more solid, anyway i looked up the one he had and someone had tested it to find out it wasnt putting out the wattage that was stated, i told him to throw that shit in the bin.

i did use it once to test a motherboard i flicked the switch on the back, it sparked and cracked and the internals of the switch failed, completely gave out with its first use. absolute joke!, i then threw it straight in the bin and picked one up from the local shop.

as for your enermax they are apparently decent, ive got a modu82+ thats been in my pc since 2015, got it from a place i worked building systems, the client changed their mind and i got it free still new, tho seems they were sold in 2008 so it was probably sat in its box on a shelf for 7 years before i got it, still good after all this time, also i noticed the fan spins after powering it off, didnt know it was a feature just assumed it had good bearings in the fan, also last week i picked up a pc with an enamax ELT620AWT thats got 28A on the 3.3v and 32A on the 5V.

i would say recap your psu if you think its worth keeping, using it as is should be fine and if it does blow it wont cause any damage to you board unless you do what my dad did and plug the floppy power into the onboard fan header. 🤣. he blew the psu and also a trace on the motherboard, it burnt a piece of the copper away to nothing and some of the coating on the motherboard, i bridged the gap with some solder, it worked and he used it for a few more months till i built him a new pc.

DudeFace wrote on 2024-09-09, 15:28:

i only picked that one up as the shop is reputable and they've sold a lot of that model, if i'd seen it on amazon or ebay i woul […]
Show full quote

i only picked that one up as the shop is reputable and they've sold a lot of that model, if i'd seen it on amazon or ebay i would have passed on it being an unknown brand, i think the one you picked up from a local shop was the best call at least if its not up to the job you can always return it, just becareful buying unknown brands from amazon or ebay, my dad bought one from amazon, an unknown brand which looked nice and had braided cables, turned out to be some cheap shit from china, it was light as a feather like there was nothing inside it, i've had cheap known brand psu's that seemed more solid, anyway i looked up the one he had and someone had tested it to find out it wasnt putting out the wattage that was stated, i told him to throw that shit in the bin.

i did use it once to test a motherboard i flicked the switch on the back, it sparked and cracked and the internals of the switch failed, completely gave out with its first use. absolute joke!, i then threw it straight in the bin and picked one up from the local shop.

as for your enermax they are apparently decent, ive got a modu82+ thats been in my pc since 2015, got it from a place i worked building systems, the client changed their mind and i got it free still new, tho seems they were sold in 2008 so it was probably sat in its box on a shelf for 7 years before i got it, still good after all this time, also i noticed the fan spins after powering it off, didnt know it was a feature just assumed it had good bearings in the fan, also last week i picked up a pc with an enamax ELT620AWT thats got 28A on the 3.3v and 32A on the 5V.

i would say recap your psu if you think its worth keeping, using it as is should be fine and if it does blow it wont cause any damage to you board unless you do what my dad did and plug the floppy power into the onboard fan header. 🤣. he blew the psu and also a trace on the motherboard, it burnt a piece of the copper away to nothing and some of the coating on the motherboard, i bridged the gap with some solder, it worked and he used it for a few more months till i built him a new pc.

Yeah, they're supposed to be between the best brands for Socket A PSUs. I've actually started looking for repair shops around my city, just to get an estimate for the reapirs (if there is something to repair). But they've been asking me for the electrical and circuit diagram of the PSU, so that they can pin point what needs to be fixed, instead of disassembling the whole unit to look for issues, wich would exponentially increase the price of repairs. I may still end up bringing it to them, maybe by actually seeing and hearing the whine, they can pinpoin eventual issues more accurately.