retardware wrote on 2021-09-15, 16:55:

Interesting.
Looking up, I found that ATX 2.4 seems to have added a minimum load requirement to -12V, which might cause problems on older stuff.

So... anybody wanna hook up a case fan -12V to 0 and see if that lets ATX 2.4 supplies start?

retardware wrote on 2021-09-15, 16:55:

Because, only reading names like "Cörsäïr", "ÖCZ", "Thërmältäkë" makes me want to skip over, this stuff imho belongs into the trash, not worthy to put on the test bench.

Certain PSU from other brands may also be built by Seasonic, in case you didn't know.

I have an Antec EarthWatts PSU made by that company.

BitWrangler wrote on 2021-09-15, 17:12:

retardware wrote on 2021-09-15, 16:55:

Interesting.
Looking up, I found that ATX 2.4 seems to have added a minimum load requirement to -12V, which might cause problems on older stuff.

So... anybody wanna hook up a case fan -12V to 0 and see if that lets ATX 2.4 supplies start?

If that 's the only difference and reason for them psus not bootin' It's worth a try.

Now. do you hook the fan +12v to ground and the fan gnd to -12v or was it the other way around ? 😉
What's the minimum requirement anyway? (too lazy to look it up)
Would a couple of LED's be sufficient since a nice high power fan would be more than the 0.3A that some psu's are spec'ed for on their -12V line.

Black to most negative and red to most positive, so black or normal 0V connection to -12V and red or normal 12V connection to 0v.

The ATX 2.4 PSU's seemed to boot fine on the P4S533 and P4S533-E, it was the motherboard that didn't want to boot with them, so I doubt putting a fan on the -12v will do anything in this situation.

Limpem wrote on 2021-09-16, 08:38:

The ATX 2.4 PSU's seemed to boot fine on the P4S533 and P4S533-E, it was the motherboard that didn't want to boot with them, so I doubt putting a fan on the -12v will do anything in this situation.

Did you measure all the voltages to be present and accurate, including the PG signal, on the powered up psu and non booting motherboard combo ?

To be honest, I didn't measure those voltages.
Although I have a multimeter, I wouldn't know how to measure it when the ATX cable is connected.

I understand Seasonic are really impressive PSUs but as far as I understand it seems like modern version of lower end brands seems to improve at every new models. I know they might not have a warranty lifetime or perfect voltages like the mentioned brand but compared to the past common PSUs things got better (or not?) in the last years at least in the protections layout design. Then I always see the usual chinese capacitors inside these low wattage PSU (even the supposed good ones sometimes) but I also see generally they improved the internal component choices and design for what they costs.
I don't know if voltage ripples can damage over the years the components but at least shouldn't we expect to at least work enough good inside the warranty period?
Lately I bought a Coolermaster MWE500 v2.0 and far from being an high end PSU it seems like they much improved the internal design beside the capacitor brand and temperature limit. With the price of the lower Seasonic you can buy almost another one brand new at the end of the warranty period. If I could afford it I would have bough the Seasonic without even thinking about it of course but for a Socket 775 mainboard is more than enough to make it last longer.

If you recap your motherboards with super low ESR capacitors to survive ripple currents and recap your PSUs to super high quality caps to avoid ripple currents, you're wasting money at one end or the other 🤣

Limpem wrote on 2021-09-18, 11:11:

To be honest, I didn't measure those voltages.
Although I have a multimeter, I wouldn't know how to measure it when the ATX cable is connected.

The connectors are open on both ends.
Just stick in the multimeter probe "nails" into the appropriate holes; they will contact with the crimped-on connector plugs of the cables coming from the PSU.
This is very easy and the risk of damage is minuscule, as the probes cannot slide away and short out things.

386SX wrote on 2021-09-18, 11:59:

I don't know if voltage ripples can damage over the years the components but at least shouldn't we expect to at least work enough good inside the warranty period?

You only know the qualities of a PSU if you put it on the test bench and meter it in various load configurations, measuring the output on voltmeter and oscilloscope.

The damage mechanism of ripple coming from the PSU is this:
The caps on the mobo/cards/peripherals are only intended to even out the ripple caused by load spikes.
This causes only minor currents, limited to very short times with long recovery times inbetween.
They are not designed to even out ripple coming from the PSU.
For this reason the ATX spec defines a maximum of 50mV PSU ripple (1%) on 5V, and 120mV on 12V.

Excessive PSU ripple causes the capacitors on boards/devices to buffer the PSU ripple also.
The consequence of this is that they are permanently loaded with continuous high currents they are not intended/designed for.
In turn they deteriorate, get hot, life expectancy is massively reduced, and early failure (bloating, leaking, explosions,...) is common.

And now think a step further:
Why do you, for example, see series of tantalum explosions on some particular boards, while the majority of the same type just behaves well and inconspiciously?
My personal guess is that very often the blame for symptomatic damage done by bad power supplies is being put onto their innocent victims.

retardware wrote on 2021-09-18, 12:44:

You only know the qualities of a PSU if you put it on the test bench and meter it in various load configurations, measuring the […]
Show full quote

386SX wrote on 2021-09-18, 11:59:

I don't know if voltage ripples can damage over the years the components but at least shouldn't we expect to at least work enough good inside the warranty period?

You only know the qualities of a PSU if you put it on the test bench and meter it in various load configurations, measuring the output on voltmeter and oscilloscope.

The damage mechanism of ripple coming from the PSU is this:
The caps on the mobo/cards/peripherals are only intended to even out the ripple caused by load spikes.
This causes only minor currents, limited to very short times with long recovery times inbetween.
They are not designed to even out ripple coming from the PSU.
For this reason the ATX spec defines a maximum of 50mV PSU ripple (1%) on 5V, and 120mV on 12V.

Excessive PSU ripple causes the capacitors on boards/devices to buffer the PSU ripple also.
The consequence of this is that they are permanently loaded with continuous high currents they are not intended/designed for.
In turn they deteriorate, get hot, life expectancy is massively reduced, and early failure (bloating, leaking, explosions,...) is common.

And now think a step further:
Why do you, for example, see series of tantalum explosions on some particular boards, while the majority of the same type just behaves well and inconspiciously?
My personal guess is that very often the blame for symptomatic damage done by bad power supplies is being put onto their innocent victims.

I understand it and agree. Usually some decades ago most common people didn't even know (me also) a lot about PSU and how much they are important, not to mention powering some high end config where some spent a lot on many components but with the cheapest PSU. But I understand its importance in the early 2000's cause a brand new cheap PSU once powered did break immedately an IDE disk and almost burned the connected vga. And it was brand new one! Also happened that brand new cheap PSUs stopped working (who knows in which way with which voltage peaks or whatever) after a couple of weeks with just 50W of load..
But lately PSU tests and reviews are more common than ever and I suppose even manufacturer begin to invest a lot more into the design of the PSU compared to the awful late 90's paper light PSUs. I know we are still far from having such quality into low end brand ones anyway. Are those high end PSU still a better choice? Of course! But on the other side modern PSU situation "feels" like being better than in the past.
What I wonder is that beside having a good PSU, maybe also the mainboard component choices/design quality make me ask how much sometimes too many modern ones seems to stop working without visible problems maybe for some micro IC that stop working, some mosfet gone, or maybe an almost invisible passive component detached somewhere.

Interesting problem you've had there , I have a very similar 470w Thermaltake PSU in my in my p4/gf4 98se build and it works perfectly with the Asus p4P800 board I have.
Glad you've got it sorted , there are some strange problems that come along with these retro builds aren't there.
Lets see some pics when you get it all finished , also , I didn't realise there were P4 boards that supported the V3 agp cards , got me thinking about my next build now. 🙄

Limpem wrote on 2021-09-15, 16:06:

I contacted both Corsair and Seasonic to ask if they have any power supplies that are still ATX 2.3 specced. All of their Consum […]
Show full quote

I contacted both Corsair and Seasonic to ask if they have any power supplies that are still ATX 2.3 specced.
All of their Consumer power supplies are at least ATX 2.4 spec.

However Seasonic also has an industrial line of power supplies.
According to their support team, both the ET2 and ES2 series are ATX 2.3 (RS is not ATX 2.3 spec).
So I ordered a SSP-600ET2 connected it to the P4S533-E and it worked immediatly!
Since this PSU is industrial, it is louder then any modern consumer PSU, not modular and not in black, but it works perfect for this old board!
Really happy I can finally complete my build 😁

Hi everyone,
I am reviving this thread because I've found something interesting regarding PSUs for this motherboard.

By accident I stumbled upon this PSU from Chieftec: https://www.chieftec.eu/products-detail/181/V … S/526/APB-600B8
The spec page lists that this PSU from Chieftec is ATX12V Version - ATX 12V 2.3. So MAYBE it COULD/MIGHT work with this motherboard (based on the post I replied to):
I haven't bought one to test if it works (yet).

The 5V rail seems to be not amazing at 20A on the 600W version (22A on the 700W one) vs 24A on the Seasonic SSP-600ET2, but maybe this PSU works with the Asus P4S533-E.

The reason for mentioning this is that where I live, the Chieftec APB-700B8 is literally half the price of the Seasonic SSP-600ET2 .

I may get one of these PSUs in the future for a retro PC related build around the Asus P4S533-E so if I do end up doing that I may try the Chieftec APB-700B8 for that.

I haven't found any reviews of the Chieftec APB-700B8 after a quick Google search, they aren't a premium brand like Seasonic but they aren't a no-name brand either, I have used their CQ-01B-U3-O case which besides being a more narrow case than expected is actually really solidly made.

They have other, more feature rich PSUs that their website also says are ATX 2.3

I don't see why people are so hung-up to get a PSU with a strong 3.3V and 5V rail for this motherboard (P4S533-E). It has s 4-pin 12V CPU connector, so it will power the CPU from the 12V rail. Also, no Prescott support from what I read here... so even that 12V load isn't going to be too high. And by the looks of the small heatsink on the Northbridge, the draw from the 3.3V and 5V rails should be relatively small. Depending on the video card used, one should be able to easily power this mobo with a 200-300 Watt PSU.

The original discussion was more about ripple currents at very high load (big thing around 2021, with some Seasonic PSUs failing at that and causing instability in systems with high-end RTX GPUs), not so much about the need for a fat 5V.

This system wasn't high-end in its day, let alone remotely comparable in terms of power draw to anything in 2021. Agreed that it could work with a 300W PSU - but be careful that a lot of low power PSUs are low end utter rubbish. In this case there's no requirement for high power, but there should be one for quality. If you can't find a decent brand low power one, it's better to go for a higher power good one than risk your system with some bottom-scraping mess.

dionb wrote on 2025-02-08, 09:27:

In this case there's no requirement for high power, but there should be one for quality.

Agreed.
And I really should have stated this in my post above, but didn't, so thank you for catching this.

Most of what I run are OEM PSUs from machines like Dell, HP, Acer, Fujitsu, and etc. - i.e. typically PSUs that were built by Delta, Chicony/HiPro, LiteOn, AcBel, Astec, and Bestec.... and very infrequently, FSP. Some of these I recap upon getting (typically the Bestec and some Delta's, but even more so the FSP's), while others I tend to leave running with the original caps (usually the HiPro, LiteOn, and Astec) unless they have failed caps already. But it's worth nothing that all of these are known good quality brands that will stand behind the numbers on their label.