replacing caps in a PSU, same spec, different size?

[logic7]

I just had a PSU crap out on me. Took it apart and found three fujjiyu 1000uf 10v caps that had gone bad. Looking in my parts bins, I found that I have three unused Sanyo 1000uf 10v caps, however they're physically smaller than the fujjiyu caps. Can I safely replace the larger caps with these smaller caps? I've never done a swap with smaller caps before and I'm hesitant to do it.

[stj]

Re: replacing caps in a PSU, same spec, different size?

if the ESR is similar.
the size is not important providing they will fit.

[logic7]

Re: replacing caps in a PSU, same spec, different size?

if the ESR is similar.
the size is not important providing they will fit.

ugh... I can't find any information on these Fuhjyyu caps (misspelled the name earlier). If the ESR is a mismatch, what's the worst that can happen?

[c_hegge]

Re: replacing caps in a PSU, same spec, different size?

It depends how far off it is and how tolerant the PSU's feedback circuit is. It may work just fine, or it might make the ripple worse.

[stj]

Re: replacing caps in a PSU, same spec, different size?

fuckyou - the manufacturer.
http://www.fuhjyyu.com.tw/

[audiofreak19]

Re: replacing caps in a PSU, same spec, different size?

That's can mess it up? I just did this on my moms psu for her computer. There were 3 bulged. I had same spec ones to and it still had the same problem after.

[stj]

Re: replacing caps in a PSU, same spec, different size?

so the problem was deeper and the bad caps didnt cause the problem.

what's the symptoms.

[logic7]

Re: replacing caps in a PSU, same spec, different size?

fuckyou - the manufacturer.
http://www.fuhjyyu.com.tw/

ugh... figures their documentation doesn't give a value for ESR.

[c_hegge]

Re: replacing caps in a PSU, same spec, different size?

If that's the case, they are probably GP caps (not low ESR caps). If that's the case, I usually use Panasonic FC, Nichicon PW, NCC LXZ, Ruby YXF or something like that. You might get away with lower ESR than that or you might not. It depends a lot on the design of the PSU.

[logic7]

Re: replacing caps in a PSU, same spec, different size?

Yeah, they're the TN series general purpose caps.

The PSU is a cheapie 300W PSU I picked up years ago, but it's the only one I have available that has a 12V P4 connector on it and the machine it was used in was still in service.

BAH... Guess I'll need to look into different caps.

[c_hegge]

Re: replacing caps in a PSU, same spec, different size?

Assuming the original Fooljyyu's were 10mm diameter, any one of the following would work:

http://www.digikey.com/product-detai...0225-ND/266235 (Panny FC)
http://www.digikey.com/product-detai...877-ND/3563691 (Ruby YXF)
http://www.digikey.com/product-detai...1746-ND/589487 (Nichicon PW)
http://www.digikey.com/product-detai...1905-ND/756421 (Chemi-con LXZ)

[linuxguru]

Re: replacing caps in a PSU, same spec, different size?

Rubycon ZL, ZLH or ZLG are worth considering - the ZLH is available in 1500uF/10V/8mm that fits in some fairly tight spots.