VOGONS


A tale of two PSUs

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Reply 180 of 472, by blackjudas

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keropi wrote:

^ last photo of this post: Re: A tale of two PSUs , right behind the power input , this was not part of the original psu.

Interestingly I abandoned this PSU , the +12v line only outputted ~11.2v ... don't know why.

Indeed, that's what I was referring to, and I understand it's a Line EMI filter, but what I really meant to ask is if it's one of your own design, or did you simply buy one from somewhere. If so, where?

I have over 100 PSU's which need repairs or cleaning, just starting to go through them and selling/giving them away after cleaning/recapping. So I found it interesting that you added an EMI filter.

11.2V loaded? That is really low =/

Reply 181 of 472, by keropi

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actually that filtering pcb was stolen from another psu , no idea where once can buy them... I believe it came from a crappy psu that had this , maybe a late attempt to make it better 🤣

yeah, 11.2v is no good, that's why it went to the naughty pile

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Reply 182 of 472, by sirlemonhead

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I have an old Antec Neo 480 that died on me, leaving a strange smell (not burning...hard to describe). I was reading this thread and decided to pop it open and take a look.. It has Fuhjyyus.

Is there any hope of repairing the PSU if I replaced these?

edit:

Well, there's the cause of the smell..
IMG_20150824_201821_b.jpg

Reply 183 of 472, by TELVM

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@ sirlemonhead: Yes, provided there is no additional djudju, if you replace that burnt resistor and recap the PSU should be OK.

In this venerable thread from 2006 you can read how a Neo 480 with the same problem was resurrected. They figured out that the burnt resistor was 1.9K Ω , and a 1.8K Ω replacement worked fine.

Notice how the dreaded Fuckyyus were dropping like flies after just two years (2004-2006). They need to be destroyed with fire before they lay eggs, and replaced with real caps.

Let the air flow!

Reply 184 of 472, by sirlemonhead

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Thanks, I think I'll give it a try 😀 I also have a dead Chieftec PSU I might try get going too.

Noobie question, but what's the deal with buying parts? 😀 Was looking here - http://ie.farnell.com/webapp/wcs/stores/servl … howResults=true and while they all have the same spec, within the same manufacturer there are different models, of somewhat varying prices? Do I just ideally grab the smallest physical height and be done with it?

Reply 186 of 472, by keropi

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Allright! It's time to recap the PSU from the ACER XT system I got recently. I believe after 26 years it's time 🤣
First of all some mandatory pics , the psu looks like it's good quality - all the caps are NICON branded (can't say I've heard of them)

th_WP_20150828_003_zpszp1fy8kg.jpg th_WP_20150828_004_zpsz7ts7hr3.jpg th_WP_20150828_010_zpskzzjdaif.jpg

th_WP_20150828_012_zps03mqsyij.jpg th_WP_20150828_008_zpsumqjrvhg.jpg th_WP_20150828_009_zpsfb6ga7pu.jpg th_WP_20150828_006_zps5rvc34xo.jpg

and here is a map of the caps used:

WP_20150828_011_zpsgfghetgu.jpg

I looked at my stash and I have these caps available:

chemicon 2200uf / 25v KZH
chemicon 1000uf / 25v KYA
chemicon 330uf / 16v KY
chemicon 100uf / 25v KY or 16v KMA or panasonic 63v FC
chemicon 1uf / 100v KMG

Are these good replacements? I don't have currently any 100uf/200v caps - I can get chemicons later or LeLon ones locally. IIRC these don't get stressed so maybe they don't need replacing?
I also have some used caps in good shape along with a capacitance meter that measures also vlos and esr - so maybe if something is really wrong I can find a good replacement.

I also noticed a big difference in size, especially in the 2200uf orange cap (is it supposed to be low-esr?) and the 330uf ones... technology has advanced it seems 🤣 🤣

As always advice/help is highly welcomed 😊 thanks!

🎵 🎧 PCMIDI MPU , Orpheus , Action Rewind , Megacard and MK8330 soundcard website

Reply 187 of 472, by TELVM

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Interesting piece of vintage hardware you got there Keropi. respect-048.gif

It has better input filtering than many gutless wonders from a quarter of a century later:

7HpTw8hM.png

The monobloc (as opposed to 'the four diode treatment') '205' rectifier bridge is good for 2A and 500V, plenty enough for this frugal application:

kusu3eu6.png

^ Those ancient Y-caps are of the 'box' type, nowadays their equivalent would be '222' lenticulars.

SQFb8Zey.jpg

GG now, to be continued ...

Let the air flow!

Reply 188 of 472, by keropi

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heh I knew this was a good quality PSU , let's see what the next of the board analysis tells us... Btw the component that you cannot see because of the big transformer is a "C65-004" , I think it's a rectifier? It has a "82" written on the bottom too.

Can't wait to hear more 😀

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Reply 189 of 472, by TELVM

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(Been busy).

The single main switcher is a 1982-vintage Texas Instruments TIPL763A rated at 8A. I wouldn't ask more than about 125W DC combined draw from this relic.

The +5V rectifier is a C65-004 which seems to be a 7.5A Schottky.

I'm not familiar with Nicon caps, but it seems this brand is/was somehow related to Fuhjyyu 😵 . From a distance they look cheap and general purpose.

Chemicons and Panasonics should be OK as replacements, just don't go too low on ESR or this ancient regulator may start oscillating.

Let the air flow!

Reply 190 of 472, by keropi

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Ultra thanks for the input TELVM, really appreciated 😀
I'll see what I can do for the 2200uf/KZH and 1000uf/KYA caps, I'll try to find not-so-low-esr replacements 😊

🎵 🎧 PCMIDI MPU , Orpheus , Action Rewind , Megacard and MK8330 soundcard website

Reply 191 of 472, by jwt27

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Rail | DC (V) | AC (mVpp)
-----+--------+-----------
+12V | +12.04 | 27.5
-12V | -11.87 | 20.0
+ 5V | + 5.00 | 22.5
- 5V | - 4.99 | 3.0

Looks like IBM picked some pretty decent caps for their 5150 PSU...

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Reply 193 of 472, by jwt27

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Yep, and also checked the big caps inside, they're all <0.05 ohm ESR. Could probably last another 30 years without servicing 😀

My brand new seasonics look bad in comparison...

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Reply 194 of 472, by carlostex

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I received an Active PFC Seasonic SS-300FS. I think this could be possible one of the best PSU's for vintage systems. Problem is i've seen some pictures around and it seems that the first caps to go are the 3300uf and the 2200uf ones right on the corner where the cables are soldered.

I got mine for 12 pounds, so i'm wondering if it was a cheap enough buy. Here are some pics:

WP_20150923_006_zpszrfhgagp.jpg
WP_20150923_007_zpsegtcajbd.jpg

I think Panasonic FR's are good replacements for these caps. Any advice for recapping this PSU is very much welcome. 😀

Reply 195 of 472, by keropi

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I see FRs on the list , so they should be fine: Re: A tale of two PSUs
Just make sure Carlos that the replacement caps are of the same size, anything bigger even by 1mm will make the recap hard...

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Reply 196 of 472, by carlostex

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keropi wrote:

I see FRs on the list , so they should be fine: Re: A tale of two PSUs
Just make sure Carlos that the replacement caps are of the same size, anything bigger even by 1mm will make the recap hard...

Yeah everything is really crammed in there, so i need to make sure they are the right size. The 3300uf ones look like they are 12.5mm in diameter and the 2200uf look like 10mm. TELVM has experience with Seasonic SS-300FS PSU's so maybe he can help me with this one.

Reply 197 of 472, by TELVM

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^ Those Pce-TUR crapacitors are FUBAR 😵 , don't even plug that PSU to the wall until you've recapped it. While you're at it you should recap everything in sight, with the possible exception of the bulk caps if they look reasonably OK.

You're lucky 😀 , the 3300uF caps in that PSU already come in 12.5mm Ø size. It's relatively difficult to get replacement caps of 3300uF in 10mm Ø, so when they come OEM in 10mm Ø you have to try to shoehorn the 12.5mm Ø in place, and this isn't always possible.

For the secondary output filtering caps Panasonic FC or FR should work fine. Make a list of the caps and their role in that PSU and we'll ponder about their replacements, something like this:

+12V: 1x 16V 2200uF 16V 12.5mm Ø
+5V: 2x 10V 2200uF 10mm Ø
+3.3V: 2x 10V 33000uF 12.5mm Ø
-12V:
-5V:
... etc ...

Let the air flow!