PC Power & Cooling Silence 750W

[shovenose]

It squeals a bit under high load - the caps were good and fine last time I checked, so I don't think it's the capacitors.
This unit had a little bit of liquid-cooling stuff spilled on it, that's why I got it for free.
But it's been working perfectly other than the squealing.
Any ideas?

[c_hegge]

I think that PSU might be similar to the Antec NeoHE 550W which I poly-modded (Assuming it's a silencer 750 Quad). After the poly-mod, it also squealed. It would be interesting to see how high the ripple is, but without an oscilloscope, that isn't going to happen.

The reason PSUs squeal is because of an oscillation in the feedback loop. The most common cause is bad caps, but in this case, getting coolant spilled on it could have something to do with it. It could be a bad SMD component. Does either side of the PCB have any evidence of anything having been spilled on it?

[shovenose]

Last time I checked ,the internals were mostly clean and I don't think any significant amount got inside. It mostly spilled on the label and one little vent, but it didn't really go in the vent that much...
Like this: http://www.pcpower.com/power-supply/sil ... sfire.html
but black matte colored...

[c_hegge]

It would be this one then (http://www.pcpower.com/power-supply/sil ... black.html). As I thought, it's one of the more standard Seasonic builds, not one of the custom built Win-tact units.

Do you have any idea which coil making the noise? If it's the yellow transformer behind the big PFC cap, then the problem is more than likely with the feedback loop, such as a small component. If it's one of the torroid coils on the secondary, then it's probably a bad cap somewhere on the secondary side.

[shovenose]

It would be this one then (http://www.pcpower.com/power-supply/sil ... black.html). As I thought, it's one of the more standard Seasonic builds, not one of the custom built Win-tact units.

Do you have any idea which coil making the noise? If it's the yellow transformer behind the big PFC cap, then the problem is more than likely with the feedback loop, such as a small component. If it's one of the torroid coils on the secondary, then it's probably a bad cap somewhere on the secondary side.

I don't know, and don't want to take it (and thus my entire PC) apart.
Next time I'm doing maintenance I'll take a look though.

[c_hegge]

If you aren't going to take the PSU apart, then forget fixing it. Any diagnosis and/or repair on a PSU is going to involve taking it apart.

[shovenose]

If you aren't going to take the PSU apart, then forget fixing it. Any diagnosis and/or repair on a PSU is going to involve taking it apart.

I meant I'll take it apart next time I have my computer opened up!

[duckula]

could it be "coil whining"?

[c_hegge]

That's what I think it is. I just want to know which coil it is. I think it's more likely to be one of the torroid coils on the secondary side.