carlostex wrote:

I only recapped one, an old Seasonic SS-300FS, and it was the easiest soldering job i have ever done. These Seasonics are really well designed and have -5V line.

Yes. - Many PSUs are so easy to recap it's not even work.
Those are very good to learn on.

I've run across some though that are full of daughter boards, strange connectors and even studs or bolts that they (seemed to) take all day just to get apart.
Those aren't so much fun.
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The Panny SU are bipolar?

keropi wrote:

It has a mix of (what I assume) crap caps and Panasonic SU series: […]
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It has a mix of (what I assume) crap caps and Panasonic SU series:

Now for the SU caps... do I replace them? Maybe replace the big ones and leave the small 2.2uf and 47uf as-is? I do have at hand these: 2200uf/25v Chemicon KZH , 100uf/63v Panasonic FC , 47uf/16v Chemicon LXY and KMG and lastly KMGs for the 2.2uf/50v ones.
What should I do? Replace all but Panasonics? Replace Panasonics too? Keep the 220uf/200v MIECs and just replace all non-Panasonic?
I lean towards replacing the MIECs and use the ones I have here to replace everything else, but maybe I am getting paranoid at this point 😵

It's interesting--they do appear to have the SU series name on the side, but I've been buying actual Panasonic SU's for use in audio projects, for years and they are in fact bipolar capacitors which do not have the side-marking for the ground-pin. The ones in your picture must be another series, though they do have what I assume is the Matsushita logo.

@Evert
Don't forget to measure the original capacitor dimension, most important is the diameter - so when you order the replacements you can get the same or smaller and they fit easily. Some PSU areas are crammed and it really helps if things fit nicely together.

Regarding the jamma psu - thanks all for the suggestions...

@PCBONEZ
yes, you know how I am thinking: recap stuff and have some peace of mind for a decade+ 😊

@PCBONEZ ,Logistics
yes, they do write SU on them but I didn't think much of it I assumed that back then (1995 or so) SU could be a different series or something... the logo seems fine UNLESS they are fake ?!

I'm going to replace 'em if the Chemicons I have here are suitable , not gonna think it twice 😎
About the MIECs, would Nichicon CS be a good replacement?

I have seen series that were offered in both polar and bipolar forms but not recently and not from any major "good cap" manufacturer.
I could be that SU was offered both ways back in the 1990's.
Also possible one kind was sold/branded under Matsushita and the other under Panasonic.
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Yes that's the Matsushita Logo.
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Please note that the silkscreen appears to be backwards on that board.
Make sure you put polarity on your cap-map.
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[Edit]
I checked my datasheet archive and amazingly I have a 2005 datasheet for Panasonic SU and they were polar.
.

There is no point in offering advice to those that don't listen.

There is no point in taking advice from those that don't listen.

keropi stated one of his goals was to have this last as long as possible.
Leaving caps that are already degraded over 10% would be not be conducive towards that particular goal.
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Yes exactly, that is exactly my thoughts when asking for recap advice. PCBONEZ got it 101% correct.
I want to service said parts and have them running OK for another 10-15-20 years. I don't care if brand caps from 1995 are "OK". I prefer OK caps from 2014-2015. You don't easily come across (for example) arcade crt monitors anymore, or arcade boards with 68000 classics.
I don't see the point cheaping out on 6-10eur and have the potential risk of frying said game pcbs, or my pentium1 build with expensive soundcards or my XT clone that I spent so many hours restoring.
It is beyond me why this concept is hard to grasp. Plus I have valued every bit of usuable advice given this far, if I was pretending to be a "know-it-all" I wouldn't bother taking pics and writing walls of text and have people waste their time answering to me so I can simply ignore their advice.
There could be a case where I didn't follow any good piece of advice by mistake or because it slipped me but it's only for these reasons, nothing more.

I hope this is the end of it, there is no need for negativity or flamebaiting in this thread . It serves noone to have any of these here.

keropi wrote:

....and here is something PSU related, a JAMMA psu 🤣

this needs to be redone! 🤣 , here is what I am thinking:

- C1 and C2 "MIEC" brand ... Nichicon CS looks fine.

Now that I finally found a datasheet for SOMETHING on that board and SU appears to be the best cap on it........
Anything equivalent to SU or better should do fine.
SU appear to be a high-ish grade of GP cap so it's like the last project where any entry level low ESR or better would be fine.
All you mentioned should work out fine. I would favor FC if I had to order any.

As to which to replace. Definitely the Giant and Elgen.
The others are probably good for a few more years so they depend on how long you want it last before the next recap.
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keropi wrote:

... About the MIECs, would Nichicon CS be a good replacement?

Quite so, CS are bomb-proof with very long endurance and humongous ripple tolerance. Good for long-term peace of mind.

Excellent then! Thanks for the suggestions 😀
I will check prices/minimum-orders and either add FCs or use the Chemicons that I have , the order is already at 85eur with the CS caps. 🤣
thanks again!

edit:
done, 90e total ... I'll use my 2200/3300 Chemicons and all the rest FCs for the jamma psu.
thanks again for all the help PCBONEZ/TELVM/Logistics 😊

wave wrote:

I have recapped and modded 3 psus from that series. I created a thread about that on badcaps. I will post a link as soon as badcaps is up again 😀

http://www.badcaps.net/forum/showthread.php?t=34418

http://www.badcaps.net/forum/showthread.php?t=46555

First of all that add on board needs to go:

http://www.badcaps.net/forum/attachment.php?a … 66&d=1389575592

Recap details:

5vsb:
1x470uF 10V OST RLP & 1x 1000uF 10V OST RLS --> 2x1000uF 16V Nichicon HE
2x1000uF 6.3V Rubycon YXG also works 😀

-12V:
1x220uF 16V JunFu HK --> 1x220uF 16V Rubycon MHE & 1x 220uF 50V Nichicon HE (there was an empty slot on the pcb for a second cap)
1x120uF 16V Panasonic FC & 1x120uF 35V Nichicon PM worked without a problem too!

3.3V:
2x2200uF 6.3V JunFu HK --> 2x2200uF 6.3V Teapo SX

5V:
5V: 2x2200uF 10V JunFu HK --> 2x2200uF 6.3V Teapo SX

12V:
1x330uF 16V JunFu --> 1x1000uF 16V Rubycon YXF
1x3300uF 16V OST RLP --> 1x3300uF 16V Panasonic FR

Fan mod
3.23kohm resistor in parallel with the thermistor (3.3kohm nominal value)

Minimum load resistors

Original --> New

5vsb: 50ohm --> 180ohm

3.3V: 15ohm (!!) --> 50ohm taken from 5vsb

5V: 50ohm --> 150 ohm

12V: 240ohm --> 1000ohm

-12V: 470ohm --> no change

Please post some before and after photos 😉

If you own an esr meter check the primary caps real capacity and esr and report back.I used 800uF 200V Panasonic EE 105C.

I recommend you'd use only Japanese capacitors for your recap. You could leave alone the small caps, but those ISOs manage to cook many of them. The fan capacitor is not important. If it's bad you may use a non Japanese cap as a replacement.

> You could leave alone the small caps

In these push-pull power supplies the two small caps on the primary side, in the base cirquit of the power transistors are very important - once they dry the transistors cannot be driven properly anymore, they heat up and finally short.

Back then I wondered why the transistors blew *again*, after replacing those capacitors it was fine. One of them was quite 'done'.

This is correct. I was reffering to the tiny caps on the secondary that are usually placed near the TL494 KA7500 sg6105d and the supervisor ICs. Those are not critical.

The 2 small caps that polarize the switching transistors are important. And even more important is the 5vsb critical cap (its value varies from 22uF to 100uF) on 2 transistor 5vsb circuit. If that caps goes bad the 5vsb could skyrocket to even 12V and kill your motherboard!

Capacitors arrived yesterday, RS offers such a great service that I don't even see the point going to local stores tbh... quality caps in 4 days? sign me up!
Excellent idea suggesting RS PCBONEZ 😊

So I finished and tested both monitor chassis and psu - as expected everything is working great 😊

CONGRATS! - Looks really good.

I've got a nonfunctional PSU here I'd like to repair, and the first thing I noticed is the fuse has blown. I saw this post earlier in the thread:

133MHz wrote:

Fuse is ceramic instead of glass so you can't determine if it's blown just by visual inspection, you'll have to test continuity across it with a multimeter.
If you find it has blown, check the rectifier diodes (or bridge) on the primary for shorts.

So I checked the bridge rectifier (while it was in-circuit) and I'm getting no resistance between the DC + and - lines, in both polarities, but nothing between the other pins. I'm a bit confused because in order for that to happen I'd have thought you'd need two diodes to be shorted, which would then mean you'd be able to measure a short between at least one other pair of pins and that isn't happening.

So I'm wondering whether the rectifier is bad or whether it's something else later in the circuit? I'm going to try desoldering the rectifier so I can test it outside of the circuit, but I just thought I'd ask what type of readings you'd expect from a working rectifier in/out of circuit.

EDIT: Forgot a desoldering iron makes it so much quicker to remove components. Testing the rectifier on its own it seems fine - no shorts between any pins. I will have to continue the hunt it seems...

I have a question about an old PSU I opened up a couple days ago (It's still in my living room actually).

Most of the time I kinda know what I have in hands (I'll add right away that I'm not at all as knowledgeable as most of the others here in this thread, but I do have some basic knowledge about what's good and what's not so good) but with this PSU I kinda have some doubts which I will try to explain.

This PSU came out of a P4 I got at a thrift store a month or 2 ago (Northwood RDRAM, just so you can place it chonologically a bit) and wasn't anything special (just some lower-end AGP card, single harddrive, optical drive, etc).

At first I kinda had high hopes it would be a better quality unit as the PSU fan exhaust grill looked very much like the ones FSP models used a lot in those days.
However...
The very first thing I did when I got the PSU out (the label wasn't readable due to part of the case obscuring it, that's why I couldn't ID the PSU before I removed it from the case) was to read the brand and to check the label.
Brand: Sam Cheer. Could've been better and as I knew very little about this brand (found maybe 1 or 2 other Sam Cheers in like 10 years so I didn't know a lot about them from top of my head).
Label: The print on the label looked very similar to the ones used by FSP models of the same era but the model number was this one: CWT-300ATX12 (PFC) and CWT was Channel Well Technologies (iirc), which was somewhere below FSP I think, but not on the bottom.
Stats on the label: 3.3V 14.0A, 5V 30.0A, 12V 15.0A, +5Vsb 2.0A, -5V 0.5A, -12V 0.5A

And for some reason a PSU with a colory sticker on it which includes the word "Pentium 4" always raises my suspicion 🤣

Anyway, I opened it up and 1 of the caps had leaked pretty bad, the rest of the PSU seemed to look alright what damage is concerned (so no burn marks on the PCB or anything, not a lot of dust) but I have not checked it thoroughly as I typically never bother when I see theres leaking caps inside.

One more thing I did find obvious, and that's how tiny the 2 largest caps looked. The typical ones are a good portion of the height of the PSU but these looked like they were dwarfs...too bad.

But anyway, would it be worth it to repair this unit? Main reason is of course it's stated 30A and that the rest of the unit didn't seem to be used a lot.

I can post pics if this could help, but these would need to be taken with a mobile phone 😵

Interested in hearing opinions about this PSU 😀

edit:
Almost forgot, this particular PSU also has one of these extra motherboard power connectors that looks a lot like 1 of the 2 plugs used on typical AT-class PSUs, so that alone might be a reason to repair it?

Please post some high resolution well focused pictures of tne psu

Malvineous wrote:

I've got a nonfunctional PSU here I'd like to repair, and the first thing I noticed is the fuse has blown. I saw this post earl […]
Show full quote

I've got a nonfunctional PSU here I'd like to repair, and the first thing I noticed is the fuse has blown. I saw this post earlier in the thread:

133MHz wrote:

Fuse is ceramic instead of glass so you can't determine if it's blown just by visual inspection, you'll have to test continuity across it with a multimeter.
If you find it has blown, check the rectifier diodes (or bridge) on the primary for shorts.

So I checked the bridge rectifier (while it was in-circuit) and I'm getting no resistance between the DC + and - lines, in both polarities, but nothing between the other pins. I'm a bit confused because in order for that to happen I'd have thought you'd need two diodes to be shorted, which would then mean you'd be able to measure a short between at least one other pair of pins and that isn't happening.

So I'm wondering whether the rectifier is bad or whether it's something else later in the circuit? I'm going to try desoldering the rectifier so I can test it outside of the circuit, but I just thought I'd ask what type of readings you'd expect from a working rectifier in/out of circuit.

EDIT: Forgot a desoldering iron makes it so much quicker to remove components. Testing the rectifier on its own it seems fine - no shorts between any pins. I will have to continue the hunt it seems...

This kind of thing can get interesting real fast and can potentially help a lot of people.
If you continue the project and are of a mind to IMHO it's totally deserving of it's own thread.
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