How to repair PSU?

[HexaPro]

Hi everyone, I want to know how to repair a PSU unit, how to identify wich part is broken and where to buy the replacement parts. Coz I've been dealing with a lot of faulty and even dead PSU. Is it possible to repair it?

Right now I have a PSU that still alive but won't boot a PC, also have one that keep making problem with the Hard Drive (damage it), Optical Drive (burning failure) and also making all the Case fans dead.

I'm really curious about fixing this thing and even make it better and more reliable than before.

[PCBONEZ]

Re: How to repair PSU?

Open a thread for each one with a title like "Need help with an xxxxxxx PSU".
xxxxxx is of course the brand or [better yet] the brand and model.

Usually someone here has worked on one like it.
-
Listing the caps helps.
Posting photos of the inside helps.
.

[HexaPro]

Re: How to repair PSU?

Ok, here's the picture. There's nothing burnt on this unit. But I've test it with DMM and the +5V would starts from 5.30V and then goes down and stay at 5.25V. The other Volts are still in normal range.

Here's the caps spec :

2x 16V 1.000uF D10mm - Nicon (Black)
1x 16V 1.000uF D8mm - Nicon (Black)
2x 16V 220uF D8mm - Nicon (Blue)
4x 10V 1.000uF D10mm - Nicon (Dark Blue)
1x 50V 100uF D8mm - BH (Purple)
3x 50V 10uF D5mm - BH (Purple)
2x 50V 2.2uF D5mm - Nicon (Blue)
2x 50V 1uF D5mm - Nicon (Light Blue)
2x 200V 680uF D22mm - LCZ (Black)

The PC won't boot with this PSU, when I replace it with other PSU the PC is booting normally. I haven't test the PG since I don't know how to test it with a DMM. But this PSU has made a Hard Drive goes faulty, and all the chassis fans are busted.

[PCBONEZ]

Re: How to repair PSU?

Okay, first.
If it's killing hard drives you may be having voltage spikes that are too fast to see on a DMM. You would need an O'scope to catch that and if you don't have access to one I'd be -really- uncomfortable about putting this one back into service even after a recap.

Some of the caps look like the first stage of bloating. Plumping up between the 'ribs' of the vent stamp but not bad enough yet to push the ribs up too.

None of those are good cap brands.

Does the PSU itself start and stay on, or just 'kick', or does it act dead?
[Can tell by PSU fan running.]

Is that +5v the standby +5v or the main +5v rail?

Chassis fans are what voltage?
.

[holmes222]

Re: How to repair PSU?

hi HexaPro ..glad to see other member from same country (i'm indonesian too) ..
i recently have a problem with cm rp-650-pcar psu
that thing have a lot of badcaps ..
my suggestion in do a full recap on secondary
my psu now run smooth and normal ..with just only 3 recap capacitor ...yes only 3 of all secondary caps..so what happen if i recap all capacitor in secondary ?? you can imagine ..the result will be awesome

@PCBONEZ .. in my country, the generic case fan running almost from +12v

[HexaPro]

Re: How to repair PSU?

Okay, first.
If it's killing hard drives you may be having voltage spikes that are too fast to see on a DMM. You would need an O'scope to catch that and if you don't have access to one I'd be -really- uncomfortable about putting this one back into service even after a recap.

Ok, I'll note that. But I don't have any O'scope.

Some of the caps look like the first stage of bloating. Plumping up between the 'ribs' of the vent stamp but not bad enough yet to push the ribs up too.

I've replaced all the output filter caps (16V 1.000uF & 10V 1.000uF D10mm) (6 Total) with a used 6x UCC KZG 16V 1.200uF just to test it. I'm planning to poly mod the PSU.

None of those are good cap brands.

You're right, I also laugh when I read the brand. Sounds like Nichicon fake, hahaha...

Does the PSU itself start and stay on, or just 'kick', or does it act dead?
[Can tell by PSU fan running.]

The PSU stay on, but it won't boot. I don't have the complete note of all the rail voltage since I think they're all fine accept for the +5V rail.

Is that +5v the standby +5v or the main +5v rail?

I've test all the rail for the +5V and it score the same value 5.25V

Chassis fans are what voltage?
.

holmes222 is right, I've checked the fan voltage and it connected to the 12V rail.

I just found out that there's a resistor that's not soldered on one lead (What a great QC). So I put in the lead into the corresponding post hole and soldered it. now the +5V reads 5.12V or 5.16V (I forgot to write it down) and it would boot the PC properly now. What a silly problem.

hi HexaPro ..glad to see other member from same country (i'm indonesian too) ..

Well, nice to meet you here too

i recently have a problem with cm rp-650-pcar psu
that thing have a lot of badcaps ..
my suggestion in do a full recap on secondary
my psu now run smooth and normal ..with just only 3 recap capacitor ...yes only 3 of all secondary caps..so what happen if i recap all capacitor in secondary ?? you can imagine ..the result will be awesome

Secondary??? What is that? I don't understand
Do you mean the output filter? The first and the last that goes to the cables? They do come in pairs [cap > choke > cap > cables (rails)]

2x 16V 1.000uF D10mm - Nicon (Black)
This is filtering the 12V rail

4x 10V 1.000uF D10mm - Nicon (Dark Blue)
This is filtering the 5V and 3.3V rails

1x 16V 1.000uF D8mm - Nicon (Black)
2x 16V 220uF D8mm - Nicon (Blue)
1x 50V 100uF D8mm - BH (Purple)
3x 50V 10uF D5mm - BH (Purple)
2x 50V 2.2uF D5mm - Nicon (Blue)
2x 50V 1uF D5mm - Nicon (Light Blue)
I don't know what these caps are filtering. I wan't to know the exact voltage value that they are filtering so I can use a good lower voltage caps to replace it.

[holmes222]

Re: How to repair PSU?

secondary i mean ..filtering output caps for all rail
the last that goes to cables ..
also the caps that near the +5vsb need to be checked if going bulged

what brand is it ?? acbel??enlight??other??

[mockingbird]

Re: How to repair PSU?

That looks like an old Young Year (Circa '99 - '01).. I tried to recap one of those, all I got was a spectacular flash and a blown fuse when I gave the thing power.

[PCBONEZ]

Re: How to repair PSU?

Fuhjyyu seems to have gotten their start as a distributor of Nicon caps.
Didn't make them, just the distributor.
.
Nicon either went *poof* or they are too small to have a web site.
Actual company name was Nicon Venus Electronic.
.

[370forlife]

Re: How to repair PSU?

Youngyear, Sunpro, Golden Tiger, etc... all make a variation of this design. It's a common design among small Chinese manufacturers. Is it worth recap? Not with high quality ones, and shouldn't be used in a working computer.

[HexaPro]

Re: How to repair PSU?

secondary i mean ..filtering output caps for all rail
the last that goes to cables ..
also the caps that near the +5vsb need to be checked if going bulged

what brand is it ?? acbel??enlight??other??

Simbadda SimCool 430W. Please don't laugh
It's not the best, but It's quite good I guess by the look of the Transistor, Rectifier, etc. I sell these SimCool and it's more stable and it's still better than those Sim-X, Mentari or Okaya PSU which always making a reboot problems. I'm thinking about replacing it with Simbadda 500W (Lifetime Warranty) when this unit is broken beyond repair.

That looks like an old Young Year (Circa '99 - '01).. I tried to recap one of those, all I got was a spectacular flash and a blown fuse when I gave the thing power.

Well I don't know about Young Year but this thing still works after I replace the 12V with a used 16V UCC KZG, 5V and 3.3V with a used Rubycon ZL 6,3V. Tested it for a few minutes and no Bang Bang :P

Fuhjyyu seems to have gotten their start as a distributor of Nicon caps.
Didn't make them, just the distributor.
.
Nicon either went *poof* or they are too small to have a web site.
Actual company name was Nicon Venus Electronic.
.

Hm... Nice info, I thought it's a local brand before.

Youngyear, Sunpro, Golden Tiger, etc... all make a variation of this design. It's a common design among small Chinese manufacturers. Is it worth recap? Not with high quality ones, and shouldn't be used in a working computer.

I dunno, but I want to try it. I like to experiment a bit with this model. My boss got a lot of these PSU from me, so I just want to make it better with less cost before it's dead for sure. And I just want to make it last before I have the budget for a better replacement. Need 20+ Units and I'm the one who's paying for it. I just found out that a bad PSU will wreck even the best Mainboard, Graphic Cards, Hard Drive, etc. And this type seem a lot stable and quite worthy for modification.