Obvious bad cap in PSU?

[pepsi_max2k]

Hey all, just wanted to know if this cap is deffinately bad as I have 0 experience myself. PSU seems fine, although it was making a slight hissing noise when the graphics card was accessed (connected via a PCIe to molex adapter), although that was stopped by connecting another 12v source to the same cable run. That made me open up and look for bad caps, and the only noticeable issue is the one on the right in these pics, very very slight bulge at top compared to the one on left, wouldn't have noticed it otherwise, bulges less that 0.5mm at most anyway. But it is leaning away from the board, which I figured might have been a cable running over the top of it pushing it to the side, but maybe not. Anyway, what d'yall think?






and a recording of the hissing noise. increase is caused by minimizing/maximizing a window, most of the rest is fan noise, it's all quieter and higher pitched irl:
http://www.inaudible.co.uk/temp/psuhiss.wav

[PCBONEZ]

Re: Obvious bad cap in PSU?

Might be, might not be.
The biggie 'beer can' caps are called 'primary' or 'input' caps by many folks here.
Many of them have a plastic disc on the top to insulate them from surrounding parts.
The disc is not part of the caps can, it's just a cover.
The disc can 'bulge' but the actual capacitor underneith isn't necessarily buldged too.
[With the power off for 5-10 minutes] push it with your finger and see if whether it lays down flat or there is something behind it pushing it up.
If it goes flat the cap isn't bulged. [It probably won't stay flat when you let go.]
If there's something pushing it up then the caps underneith it is buldged too.

.

[PCBONEZ]

Re: Obvious bad cap in PSU?

"With it off" - meaning: unplugged.
Heat sinks in PSU's can be energized parts.

[Krankshaft]

Re: Obvious bad cap in PSU?

Might be, might not be.
Many of them have a plastic disc on the top to insulate them from surrounding parts.

Good point it's not the first time I've seen the plastic disc pop up a bit but unfortunately I can't see the tops of the caps well enough in the pics provided.

I had a similar question with an Antec PSU they were UQ caps instead of UP but they still were Panasonic.

Here:

https://www.badcaps.net/forum/showthread.php?t=5600

Panasonic UQ series on that PSU I measured them with an ESR meter and they matched the cap with a slight bulge and the one not were identical. So it was a false alarm.

Besides these still were Panasonic caps after all so I left them alone.

I replaced every Fukyuu in that PSU including the GPs so I had enough on my plate.

[pepsi_max2k]

Re: Obvious bad cap in PSU?

couldn't get my finger under the heatsink, so tried a wooden stick, and it didn't seem to want to get pushed down. bulge is about as small a bulge as you can get without it being flat, but is highest in center and seems to have a few lines coming off from center to sides, but it's so slight i can't really tell (could just be dust and bad lighting), and i can't get a better pic of it at all.

also the plastic sides that round off over the top are slightly higher than on the left, and that line at the top where it just starts to fold over (the one with the light reflecting off it more in the pic, and the other slight line above it, they appear to be very slightly wider appart on the right than on the left.

but other than that i can't see any difference. so i guess i'll just hope it's ok unless i get any other issues, and try to get a replacement soon as i can.

[PCBONEZ]

Re: Obvious bad cap in PSU?

The height difference is probably due to the space underneith them.

They are on line voltage (AC power) and their job is different from the filter caps on the DC side.
I wouldn't worry about them too much.
The primaries rarely go bad short of damage from a big AC power surge.
When they do go bad usually the unit doesn't work at all.

.

.

[i4004]

Re: Obvious bad cap in PSU?

mhm..bulging panasonic, and on primary side...rare indeed....

change them, and check/change resistors encircled in red on this image

[Harvey]

Re: Obvious bad cap in PSU?

Is it bulging at the bottom or is there another reason its lifted away from the PCB where it used to be glued down?

[pepsi_max2k]

Re: Obvious bad cap in PSU?

Had a good look but couldn't see underneathe too well, although there was no leakage where i could see. As for other reasons, I originally thought it was that blue and brown cable running over the top of it doing it. It looks pretty tight, and I've seen a different revision and the cable runs around the side of them instead of over the top, could be a reason for it... but I dunno.

[Oklahoma Wolf]

Re: Obvious bad cap in PSU?

Anyway, what d'yall think?

I think you forgot to mention that the secondary is crammed full of Fuhjyyu caps and this is a 4+ year old Topower built unit

Just to clarify my opinion from jonnyGURU forums, because I think I forgot to mention it, I think your noise problem is likely due to the secondary caps, even though I still have doubts about that one primary cap.

The fact is, Fuhjyyu sucks the big one and your unit dates from right in the middle of Antec's big Fuhjyyu foulup. I've seen these fail almost as often in Topower units as they did in the Antec ones. And Topower still uses them too, under the name Asia-X.

[pepsi_max2k]

Re: Obvious bad cap in PSU?

Thanks Oklahoma, thought I should get a 2nd opinion here just incase thanks for the help anyway, i'm just gonna hope the primary is good enough until I find a decent PSU to replace it, and I did have a good look at all the fuhjyyu's and none look like there's anything wrong there, so again I'm just gonna hope it holds out til it's replaced

[PCBONEZ]

Re: Obvious bad cap in PSU?

FUHJYYU!

OH ICK...
I need to shower now!!!

[Toasty]

Re: Obvious bad cap in PSU?

FUHJYYU!

OH ICK...
I need to shower now!!!