Power supply and components failing -- Odd Smells to add

[Flimmy]

As time goes on, the questions and possibilities for the effects of the problems are growing. I guess, or something like that.

Basically, I had in my possession three power supplies, two of which were going bad and one that was cheap. The cheap one posed to be quality some years back when 80+ certified was something I was learning about, and it goes that the cheap PSU was not 80+.

Before I realized the first PSU was bad, I used it in a system, which may have permanently caused some component deterioration.

The next case is that the other PSU had been used at max capacity for long enough to give some flags. It was the case of underestimating power draw on an old system.

So that leaves this with three bad PSUs and the remnants of the two systems that went through it.

Now, the story goes that after this conditioning, a smell began to show from something. At first it seemed like something else other than effected components, but I don't really have much proof of this.

The short of it is that I am trying to track down this odor. After a new PSU was purchased and the other three put into RMA or retirement, the smell persisted. Another thing: two Radeon 6970's were run in tandem for a long time and also began to fail, probably due to the PSU that was taxed a fair amount. At some point, unsure of their condition, one was used, and immediately emitted a smell on system start up. So both have been sort of scrapped as well.

Now there are the components left. One motherboard is slightly cracked in the cheaper system. Two RAM sticks seem to encourage a smell, although that could be due to the other motherboard suffering through the failing PSUs. The CPU was overheated multiple times, and was reinstalled without proper thermal conditioning at some point.

I am looking at actually replacing the necessary parts with new counterparts to try to solve the elusive problem completely because it could be a case for total futility to salvage.

1st system w/ overheated CPU, overtaxed PSU, and possibly smelly GPUs:
Intel i7 4790k
x2 Radeon HD 6970
B85M motherboard
Team Vulcan 8x2 RAM
Seasonic S16G PSU
x2 120mm fans (possible to salvage?)

2nd system w/ light crack, went through PSU failure, might also be victim to GPUs
Celeron G1650
4GB RAM
Radeon HD 6970 (reused from other system temporarily)
?? MSI motherboard
Xigmatec PSU (that failed and produced odor)
Antec 450W Basiq Power (just cheap)

I don't think I can salvage the GPUs, the RAM (?), or either motherboards. But what's unsure is the CPUs, and the worth of replacing said parts to reuse them.

[R E D L I N E]

Look for swollen or leaking capacitors on the motherboards, they can smell really badly when they're under load and venting

[Flimmy]

After some more guesswork, the capacitors aren't showing any visual signs of failing. Though, the capacitors are solid.

I checked the onboard audio, and circumventing it didn't improve much.

There's still a persistent, but mild, smell that is sort of awful. Could be a laptop problem as it was running when the smell was present recently. Smelling near the components didn't seem to give a direct sign. It's more of an ambient odor that is hard to detect the source of.

If, per chance something on the main motherboard was going bad, could it spread this decay to other parts? The PSU was new because the other is going to be replaced, but if I were to use this new PSU, exposed to the old parts as it is, I'm not sure if it would cause more problems. As if the new PSU has gotten part of the component decay or something.

I think it's time to change something up to take a more direct approach.