I removed the third stick of RAM, still resumes properly after 7 tries.

This is the mismatching Kingston added 2 years ago.

Great, there goes the RAM upgrade.

It may or may not be the stick itself. Might be the slot, or just the fact that 3 sticks are more taxing than 2 on the standby rail...

Yup, the third stick by itself in its usual 3rd slot is fine. I'll see what new PSU does. Hope it's really not some random capacitor on the motherboard.

After putting things back like they were, the situation has worsened radically. Turning it on after plugging the power, same symptoms as before with resume from sleep. After another power cycle, same. I unplugged one of the disks and then it seemed normal, until going into BIOS and trying to put things like they were (no CMOS battery), after couple of seconds, screen went all garbled. It responded to power button and shut down. Now I've unplugged the power and I'll leave it as is until the new PSU arrives. It might already be too late.

Seasonic ones are somewhat more expensive and for some reason, the places I looked at don't have any clear information on the warranty besides standard 2 years. ASUS TUF Gaming 750W Bronze is clearly marked to have 6 years warranty. Eh, considering where the world is headed, I'm probably not going for another 17 years. There are claims even some Seasonic models may not be too special, depending on the market and to whom the manufacturing was outsourced, but what do I know.

I'll see next week what still works and not. If it's clear there's no POST with core components, I may use Raspberry Pi 5 for a while, maybe eventually just get a modern motherboard, CPU and RAM and keep the rest of components.

If I'm not mistaken, ATX is still ATX when it comes fitting the motherboard in the case, right? My case has cage for HDDs, obscuring the full length, I've read this design doesn't mix well with modern graphics cards that have significantly grown in length, should I consider a new graphics in the future, but considering my interest in gaming is nowhere where it used to be, that may not be a concern. Cheap graphics cards are still normal length.

I anxiously installed the new power supply, had some fun with cables along the way and now I'm typing from the same old computer. I'm anxious to run any stability test.

BTW, I checked today and noticed, my case doesn't seem to have power LED cable (so that part of panel connector on the motherboard is unused), even if the cable is pictured in the manual (unless it's actually well hidden...). I suppose I could improvise the LED if I was the creative type. Motherboard's manual indeed does mention the LED blinks when in sleep mode. The case's manual is for few other variants of the case, mine is Aerocool V-Touch Pro (the others being Aerocool V-Touch and Aerocool V-Touch A). Don't know what's A, but if I remember right, the difference between Pro and plain one is in huge side fan Pro has.

And the photos of cables in case's manual for other things on motherboard's panel connector like power switch and reset button, wires are colored differently.

Another weird thing I have from before, the 24-pin ATX 12V extension cable. Rather short and seemingly pointless, except that it's got 3-pin connector wired in the middle. This plugs to another cable going towards case's LCD screen. I guess that's how the screen is powered.

UCyborg wrote on 2026-03-21, 13:09:

Seasonic ones are somewhat more expensive and for some reason, the places I looked at don't have any clear information on the warranty besides standard 2 years. ASUS TUF Gaming 750W Bronze is clearly marked to have 6 years warranty. Eh, considering where the world is headed, I'm probably not going for another 17 years. There are claims even some Seasonic models may not be too special, depending on the market and to whom the manufacturing was outsourced, but what do I know.

As Far as I know all the recent seasonic ones I have had have a 10 year or 12 year warranty. Seasonic has been making making PC power supplies since the early '80s as an OEM for many other brands. Again as far as I know they dont outsource the psus they make, other companies outsource to them to make psu models for them. (some Corsair models are made by Seasonic for example)

For older PSUs I always used this list: https://web.archive.org/web/20230512115304/ht … ewDatabase.html to see who the OEMs are for different PSU brands. (had to use wayback machine as the website seem to go defunct late 2023). I'm not sure when the stopped updating that site but it was well before 2023.

I see. Maybe I rushed it a bit. I found 650W Seasonic G12 GC at one reputable local shop which I missed. This one would be sufficient wattage-wise. Though the official website says it has 5 years of warranty. 750W is a bit of an overkill for this PC.

Still, ASUS TUF Gaming variant shouldn't be too bad to be nervous about? Hopefully.

Technically, the bronze rated ones may consume a bit more electricity than needed than gold rated ones, is that right?

A little late, but my 2 cents worth on the matter:

O/P's system uses a motherboard with an nVidia chipset from around the late bumpgate era (MCP78).
The old PSU may or may not be to blame. If it was mine, I would not have replaced it without first opening it for an inspection. If it uses good quality Japanese caps, I'd say 99% chance that the PSU was *not* the issue. However, if the PSU uses non-Japanese caps, then it would be a coin toss between that and the chipset (I personally would still bet on the mobo chipset, given my experiences with various nVidia chipsets - I absolutely despise anything with them at this point.)

That said, it's still not too late to open the old PSU and check what's in it (if you have the time). Maybe post pictures too? I used to read PSU reviews back in the day and more or less had an idea of who built what an what was in which PSU... but I just can't remember anymore what these particular LC Power PSUs were like on the inside. All I remember is they weren't low-end PSUs by any means.

cyclone3d wrote on 2026-03-17, 17:59:

Seasonic. […]
Show full quote

Seasonic.

Make sure you get at least 80+ Bronze certified.

I will trust no other brands for the most part unless I can verify the OEM that made them and can find actual testing done on them in regards to efficiency and ripple.

All others should be treated as unreliable.

One should NEVER go by the brand alone.
Or reviews in regards to ripple and efficiency.
None of these matter if the PSU uses shitty caps that will go bad in some/more years down the road. Even the warranty can be irrelevant.

Just check out this Seasonic B12 BC-550 I posted about a year ago on badcaps:
https://www.badcaps.net/forum/troubleshooting … ad-caps-already

^ In short, the thing was not even 2 years old and already developed bad caps. Sure, it had a 5 year warranty, and I suppose I could have sent it back to Seasonic for a replacement (though doing that after getting it 2nd hand, I somehow doubt they would have accepted it back.) But luckily, I didn't even happen to notice it had a 5 year warranty and simply went right into it and recapped it. FWIW, I'm much happier I did that - no fiddling with RMA and possibly paying ridiculous amounts for shipping. Just a few caps and a weekend afternoon to get it recapped is all it needed.

Ugh, the echoes of capacitor plague era, huh? That purplish color of capacitors on the photos you posted does give me the anxiety, Linksys WRT54GL uses such, though not sure of the brand. That was the most retro functional device I had until about 2 years ago when it was fried after return of power after outage. I gathered its power supply has rather bad caps too.

This PC was initially meant to be based on what was called AMD Dragon back in the day, but they didn't have have the motherboard I wanted and somehow ended up with this one with NVIDIA chipset.

I never opened any PSU before, I could try opening the old one, probably for the weekend.

UCyborg wrote on 2026-03-24, 21:35:

Ugh, the echoes of capacitor plague era, huh?

Sadly, not echoes, as bad caps still show up in all sorts of things. Fixed a 24V PSU last month that's commonly used for powering home LED lighting. The thing was also barely 2 years old and already fully cooked. And last week I got me a 12V LED PSU to fix that was made in mid 2019.
So yeah, bad electrolytic capacitors will probably remain a problem for a long time.
The only reason they are not a problem on motherboards anymore is because motherboard manufacturers have switched to solid polymers and/or hybrid polymers.

UCyborg wrote on 2026-03-24, 21:35:

That purplish color of capacitors on the photos you posted does give me the anxiety, Linksys WRT54GL uses such, though not sure of the brand. That was the most retro functional device I had until about 2 years ago when it was fried after return of power after outage.

That's exactly how mine died as well. Unfortunately, the buck voltage regulator circuit in that thing doesn't do well once the caps fail bad enough, so the result is *something* (IC) gets taken out from the resulting voltage spikes. I still haven't figured whether that's the RAM or the main controller on mine. Maybe will try one day when I have more time than I know what to do with (which might not be in this lifetime, the way it seems now 🤣 )

UCyborg wrote on 2026-03-24, 21:35:

I never opened any PSU before, I could try opening the old one, probably for the weekend.

It's easy-peasy.
I do it all the time, typically right on the spot whenever I buy a PSU from the local flea market here (I always carry a screw driver and some other tools with me.) Though I do it for a different purpose - just to make sure there aren't any roaches or anything like that inside. Normally I can tell by the smell. Buy sometimes a heavy cigarette smell from a former smokers PC can make it hard to tell.
In any case, just make sure the PSU is unplugged when doing this.