What do you mean when you say that the 3.3V rail is stressing the power supply by "pulling 0.35V more than it's allowed"? Is there a voltage drop or do you mean it's using more current than it should (in that case it would be amps, not volts). And how exactly would that translate to an issue with the capacitors? I'm not following the line of reasoning here.

Assuming that it is indeed a capacitor problem, my recommendation would be to stay with electrolytics of the same type that the originals. Using polymers on a late 90's board won't provide any noticeable benefits, it will be more expensive and, as you've found out, it will make it harder to find adequate replacements. When it comes to retro hardware, polymers are mostly useful on later boards to replace ultra-low ESR caps that are no longer in production.

TheMobRules wrote on 2021-04-09, 18:23:

What do you mean when you say that the 3.3V rail is stressing the power supply by "pulling 0.35V more than it's allowed"? Is there a voltage drop or do you mean it's using more current than it should (in that case it would be amps, not volts). And how exactly would that translate to an issue with the capacitors? I'm not following the line of reasoning here.

Assuming that it is indeed a capacitor problem, my recommendation would be to stay with electrolytics of the same type that the originals. Using polymers on a late 90's board won't provide any noticeable benefits, it will be more expensive and, as you've found out, it will make it harder to find adequate replacements. When it comes to retro hardware, polymers are mostly useful on later boards to replace ultra-low ESR caps that are no longer in production.

Hey, thanks for the reply! I should've been more clear with the statement regarding how much voltage the 3.3v rail would control: the motherboard's hardware monitor always reports a load of around 3.65 volts. This was not a problem with the PSU itself (which is now dead) as the computer it originally came with only drew 3.34v when it was the one using it. I can't really trace the source of the issue down to anything else other than the capacitors becoming dysfunctional since this P2B doesn't work with another PSU I own which I know works. It powers on sometimes, but in most cases, the fans twitch and nothing else happens.

Also, if polymer capacitors won't do it, I'll just resort to the next most reliable and resistant choice (going to guess it's electrolytic capacitors and nothing else.) I've heard that since polymer capacitors aren't liquid-based, they last longer and provide steadier performance, though I'd only be looking for the former aspect.

PKFreeZZy wrote on 2021-04-09, 21:37:

Hey, thanks for the reply! I should've been more clear with the statement regarding how much voltage the 3.3v rail would control: the motherboard's hardware monitor always reports a load of around 3.65 volts. This was not a problem with the PSU itself (which is now dead) as the computer it originally came with only drew 3.34v when it was the one using it.

If the 3.3V line shows 3.65V then I would be more inclined to blame the power supply rather than the motherboard, but those early hardware monitors from 90's boards are known to be notoriously unreliable. I strongly suggest measuring voltages with a multimeter first, even the cheapest ones will be much more precise than the BIOS. Also, the 3.65V reading is just the voltage between that line and ground, the "load" would be the current (in amps) that is being drawn by the board at a certain point, but you need a meter to measure that.

PKFreeZZy wrote on 2021-04-09, 21:37:

I can't really trace the source of the issue down to anything else other than the capacitors becoming dysfunctional since this P2B doesn't work with another PSU I own which I know works. It powers on sometimes, but in most cases, the fans twitch and nothing else happens.

PKFreeZZy wrote on 2021-04-09, 21:37:

Also, if polymer capacitors won't do it, I'll just resort to the next most reliable and resistant choice (going to guess it's electrolytic capacitors and nothing else.) I've heard that since polymer capacitors aren't liquid-based, they last longer and provide steadier performance, though I'd only be looking for the former aspect.

The "power on sometimes" issue can indeed be a capacitor problem, do any of them look bulged on the top or is there traces of leakage around them? In any case, if you can provide the brand and series of the current caps I can suggest some equivalent options, if you go with electrolytics from a reputable brand they will last very long under normal conditions, unless you run them inside a very hot case that cooks them. If you still really want to go with polymers, keep in mind that it will be very difficult (or even impossible) to find replacements if the capacitance is too high. In that case there are some "rules of thumb" of how much you can lower the capacitance, but I don't know what effect it could have on the circuit.

TheMobRules wrote on 2021-04-10, 00:06:

If the 3.3V line shows 3.65V then I would be more inclined to blame the power supply rather than the motherboard, but those earl […]
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PKFreeZZy wrote on 2021-04-09, 21:37:

Hey, thanks for the reply! I should've been more clear with the statement regarding how much voltage the 3.3v rail would control: the motherboard's hardware monitor always reports a load of around 3.65 volts. This was not a problem with the PSU itself (which is now dead) as the computer it originally came with only drew 3.34v when it was the one using it.

If the 3.3V line shows 3.65V then I would be more inclined to blame the power supply rather than the motherboard, but those early hardware monitors from 90's boards are known to be notoriously unreliable. I strongly suggest measuring voltages with a multimeter first, even the cheapest ones will be much more precise than the BIOS. Also, the 3.65V reading is just the voltage between that line and ground, the "load" would be the current (in amps) that is being drawn by the board at a certain point, but you need a meter to measure that.

PKFreeZZy wrote on 2021-04-09, 21:37:

I can't really trace the source of the issue down to anything else other than the capacitors becoming dysfunctional since this P2B doesn't work with another PSU I own which I know works. It powers on sometimes, but in most cases, the fans twitch and nothing else happens.

PKFreeZZy wrote on 2021-04-09, 21:37:

Also, if polymer capacitors won't do it, I'll just resort to the next most reliable and resistant choice (going to guess it's electrolytic capacitors and nothing else.) I've heard that since polymer capacitors aren't liquid-based, they last longer and provide steadier performance, though I'd only be looking for the former aspect.

The "power on sometimes" issue can indeed be a capacitor problem, do any of them look bulged on the top or is there traces of leakage around them? In any case, if you can provide the brand and series of the current caps I can suggest some equivalent options, if you go with electrolytics from a reputable brand they will last very long under normal conditions, unless you run them inside a very hot case that cooks them. If you still really want to go with polymers, keep in mind that it will be very difficult (or even impossible) to find replacements if the capacitance is too high. In that case there are some "rules of thumb" of how much you can lower the capacitance, but I don't know what effect it could have on the circuit.

Hey hey, sorry for the late reply! I spent some time looking for capacitors, but I can only find electrolytic capacitors of matching rating. I guess I'll just go with those, assuming I won't need to replace them anytime soon.

There do not seem to be any obvious signs of failure on the motherboard. The power supply acting up and 3DMark2000 crashing to the desktop consistently under a specific circumstance, and perhaps also Speedsys 4.38 sometimes producing visual artifacts on one graphics card are the main reason I'm suspicious of it. The one power supply I'm using has also made it produce sparks where the On/Off switch header is located... ouch.

Pretty much all boards of that age have failed capacitors. My Personal experience is that those boards went unstable at around 10 years of age due to failing capacitors and my recent experience shows about 50% of boards I get from the scrap yard from the late 90s to 2003 period have bulged or leaking caps. It's costing me a fortune but on all the boards I want to keep I recapping them with Panasonic FR's. (but anything will be better than old dead ones). Panasonic FRs should last 20+ years no problem