PSU worth replacing caps?

[mikay786]

Struggling to decide whether it is worth replacing some caps in a PSU I have or would it be too risky to use again in system?

Concern being if it blows and wipes out the system.

I got it with a PC, seller witnessed it go fizz, pop, smoke and shutdown. I got it and its actually still working, made a buzzing noise when I plugged it in but subsided after a few seconds and ran fine for a few hours.

Had a look inside a can see 3 caps that look bad, see pics below.

PSU is a Topower Top-1100W modular PSU, so a decent unit.

[LDSisHere]

Re: PSU worth replacing caps?

That supply should be worth recapping but it will not be easy. It would be important to pick the correct replacements and get them from a reliable source. Do not buy them off Ebay and you need to match the specifications of the original capacitors.

The reason it will not be easy is that it most likely has a double sided PCB so you need a really good soldering iron to tackle this job. Also if your soldering experience is limited you need to practice before trying to tackle this job.

For future reference you should post a power supply questions in the Power Supply Design and Troubleshooting section of this forum.

[c_hegge]

Re: PSU worth replacing caps?

Agreed. I'd have no hesitations about recapping a PSU like this and using it in a PC. If you do a complete re-cap with entirely Japanese caps, You will actually end up with a PSU that is more reliable and less likely to fail than a brand new one.

EDIT: see https://www.badcaps.net/forum/showpo...&postcount=274
and
https://www.badcaps.net/forum/showpo...&postcount=283

That thing was in far worse condition than yours, and I have it in almost daily use in a PC now after repairs.

[retiredcaps]

Re: PSU worth replacing caps?

Ahh, more Capxon (aka Crapxon) bad capacitors. I love them because I get all sorts of free stuff from owners who toss out the non working computers, TVs, etc.

Easy fix (unlike troubleshooting a TV main board) with the soldering iron and some new caps.

[mikay786]

Re: PSU worth replacing caps?

That supply should be worth recapping but it will not be easy. It would be important to pick the correct replacements and get them from a reliable source. Do not buy them off Ebay and you need to match the specifications of the original capacitors.

The reason it will not be easy is that it most likely has a double sided PCB so you need a really good soldering iron to tackle this job. Also if your soldering experience is limited you need to practice before trying to tackle this job.

For future reference you should post a power supply questions in the Power Supply Design and Troubleshooting section of this forum.

Thanks guys for all of the responses, puts my mind at ease. And noted regarding correct section.

I've done some recapping before on a motherboard which turned out well.

I have a Duratool desoldering station / gun which works well and was reasonably priced. It paid for itself fully with the repair on a motherboard I did.

Not done a PSU before but will post on here and will order caps from badcaps.

Will I get away with just doing the 3 leaky caps or will I have to do all of them?

[mikay786]

Re: PSU worth replacing caps?

Also I have a bit of a irrational fear (probably not irrational) of messing with internals of a PSU.

Just to confirm PSU should auto discharge after a few hours? and secondly its only the two large caps that you need to be careful with? So what would be the best and cost effective way of discharging the two large caps to be double sure?

[c_hegge]

Re: PSU worth replacing caps?

A few minutes is usually all it takes. If you want to make sure it's discharged, you can just short the two terminals of the big PFC cap with a screwdriver or a wire. It might spark a bit if the cap has some charge left, but doing so will almost instantly discharge the cap. Just don't do it while the PSU is plugged in.

[stj]

Re: PSU worth replacing caps?

if you have a meter, just meter the large caps to check for residual voltage.

replace all electrolytics oher than the mains ones,
caps dont always bulge when they are failing.

post a list of the caps,
list:
the designation on the pcb,
the make, series, diameter, voltage and u.f.

then the best replacements can be worked out.

[mikay786]

Re: PSU worth replacing caps?

Measured with voltmeter and appear to be discharge, touched a screw driver across them just to be sure and seems fine to handle now.

Ill have to remove them to get a proper look but have removed pcb from casing to get a better look.

The 3 dodgy looking ones are all capxons

Capxon 10v 2200uf
2 x Capxon 16v 3300uf

and other which appear ok but you can see in pics, ill remove them over the next couple of days to get a better look

[c_hegge]

Re: PSU worth replacing caps?

As stj said, Replace all of the caps on the secondary side, even if they aren't yet bulging, as they won't be far off it.

As for replacements, badcaps.net doesn't carry anything that is a suitable replacement.
For the 2200uF 10V caps, you could use either Rubycon YXJ from RS components (see http://uk.rs-online.com/web/p/alumin...itors/7497142/) or Nichicon HE from element 14 (http://uk.farnell.com/nichicon/uhe1a...tor/dp/1823552), both of which are UK based suppliers.

If you have any 3300uF 10V or 6.3V caps, you have two options. Ruby ZJL from element14 (http://uk.farnell.com/rubycon/6-3zlj...rad/dp/2346439). You can also PM our member "Behemot" and get Chemi-con KYA 3300uF 6.3V caps. (note that you can safely replace 10V caps with 6.3V caps, as they will only be on the 5V or 3.3V rail)

For the 3300uF 16V, you would have to get Behemot to supply them (either Samxon RS or NCC KZN), as he is the only one I know of who sells 3300uF 16V caps in 10mm diameter. Annoyingly, though, he doesn't sell any 2200uF caps, otherwise, I'd suggest getting everything from him. You may get away with replacing the 2200uF caps with 3300uF, but not all PSUs will play nice with it.

EDIT: This thread has been moved to the appropriate forum.

[mockingbird]

Re: PSU worth replacing caps?

Another option for 6.3V 3300uF caps is Panasonic FK:

http://uk.farnell.com/panasonic-elec...rad/dp/1744878

Double the price of the ZLJ, and the spec is probably only half as good. The difference between ZLJ and FK is aqueous vs non-aqueous electrolyte. Some people prefer non-aqueous caps.

But I also recommend Behemot. And c_hegge mentioned using 3300uF instead of 2200uF. Absolutely you can do this. Regarding the 16V 3300uF cap, Behemot sells two options as c_hegge mentioned. I highly recommend the KZN over the Samxon RS for this application, because your PSU will probably need the extra ripple suppression. Just keep in mind it is a 40mm long cap, so you might have to do some maneuvering to get it in.

[mikay786]

Re: PSU worth replacing caps?

Wow WHAT a difference a good clean tip makes! Struggled with first two, tip was a little charred so swapped with a new one a the rest were a breeze. Cant recommend these desoldering guns enough. There were a couple more tiny ones which are quite difficult getting to which ive left. So we have

A) 2 x Toshin Kogyo 3300uF 10v (UTWKZ)
B) 1 X Toshin Kogyo 2200uF 16v (UTWKZ)
C) 2 x Capxon 3300uF 16v (C725)
D) 1 x Capxon 2200uF 10v (C723)
E) 2 x Samson 2200uF 10v (SGF)
F) 1 x Samson 470uF 16v (SKM0702)
G) 1 X Samson 220uF 16v (SKM0702)
H) 1 x Samson 2200uF 10v (SGF0702)

[c_hegge]

Re: PSU worth replacing caps?

Yup. I'd suggest sending Behemot (https://www.badcaps.net/forum/member.php?u=15285) a PM. I've ordered caps from him a few times before.

[Stefan Payne]

Re: PSU worth replacing caps?

As stj said, Replace all of the caps on the secondary side, even if they aren't yet bulging, as they won't be far off it.

I think you mean:
'replace all the caps', not just on the secondary side...

I'd rather not risk using any old cap in an almost 10 Year old unit (and I woudn't use them in a modern system due to rippelastic load of modern components)...

[stj]

Re: PSU worth replacing caps?

primary smoothers are expensive - your right about changing them, but the price deters people.

mikay - you didnt list the cap diameters: 5mm, 6.3mm, 8mm, 10mm, 12mm etc.

[Behemot]

Re: PSU worth replacing caps?

Annoyingly, though, he doesn't sell any 2200uF caps, otherwise, I'd suggest getting everything from him. You may get away with replacing the 2200uF caps with 3300uF, but not all PSUs will play nice with it.

KYBs 2200/16 are on the way though it is getting somewhat longer. I expect them by late august/beginning of september.

[mikay786]

Re: PSU worth replacing caps?

A) 2 x Toshin Kogyo 3300uF 10v (UTWKZ) D 10mm H 30mm
B) 1 X Toshin Kogyo 2200uF 16v (UTWKZ) D 10mm H 25mm
C) 2 x Capxon 3300uF 16v (C725) D 10mm H 30mm
D) 1 x Capxon 2200uF 10v (C723) D 8.2mm H 25mm
E) 2 x Samson 2200uF 10v (SGF) D 10mm H 20mm
F) 1 x Samson 470uF 16v (SKM0702) D 8.2mm H 15mm
G) 1 X Samson 220uF 16v (SKM0702) D 6.2mm H 10mm
H) 1 x Samson 2200uF 10v (SGF0702) D 8.2mm H 30mm

Would it be possible to source suitable caps from say Farnels as is local to me?

[Behemot]

Re: PSU worth replacing caps?

H) 1 x Samson 2200uF 10v (SGF0702) D 8mm H 30mm

This is for real? Could you get me some clear sharp pictures when you remove it from the unit?

[mikay786]

Re: PSU worth replacing caps?

This is for real? Could you get me some clear sharp pictures when you remove it from the unit?

see attached

[mikay786]

Re: PSU worth replacing caps?

regarding D & H

See fit in board and space left behind