PCI-E question

[Wallaby Dan]

Psu's and motherboards killed by bad pcu's just don't mix. My computer uses 10 year old tech. But the pcu is new.

 

[ikonix360]

Certain caps in the power supplies usually fail and once replaced with new quality caps the supply is usually good for at least a few more years.

What i feel really helped this supply is the fact that I pulled a lot of air through it due to the high speed fan which kept the supply much cooler when operating the Windows XP computer.

Interestingly enough the voltages were well within tolerance so I caught this before any damage could be done.

That said if I had any doubts at all about the power supply I wouldn't use it.

My background is in avionics so I take great care to be sure things are as reliable as reasonably possible.

 

[ikonix360]

Here's the caps I need.

3300uF 6.3V X1
2200uF 6.3V X1
2200uF 16V X2
2200uF 10V X1
1500uF 10V X1

Only the first two were bad, although they were a different brand than the others.

The rest will be replaced as well given they are also on outputs.

So to simplify things and maybe make things more reliable I'm going to do the following.

3300uF 16V X1
2200uF 16V X4
1500uF 16V X1

https://www.mouser.com/ProductDetail/Panasonic/EEU-FS1C332?qs=gt1LBUVyoHnlvdXlIIEHIA==
https://www.mouser.com/ProductDetail/Panasonic/EEU-FS1C222LB?qs=gt1LBUVyoHkfE%2BJ4asjrXQ==
https://www.mouser.com/ProductDetail/Panasonic/EEU-FR1C152B?qs=n1SRcuzDZT0Rkl1fk38zLg==

Total cost $14.98

Now if this was a new or newer motherboard than 2010 I'd use a new supply as I would expect the computer to be usable for longer than this one will be.

 

[Joe C]

Best to just cough up $40. and be done with it.....but that is only what I would do.....
https://www.staples.com/EVGA-ATX12V-EPS12V-Power-Supply-400W/product_IM1VZ8522?tid=US&storeId=10001&AID=13957703&PID=3938566&cvosrc=affiliate.cj.3938566&cvo_campaign=Other&cm_mmc=CJ-_-3938566-_-3938566-_-13957703&CID=AFF:3938566:3938566:13957703&CJPIXEL=CJPIXEL&cjevent=9358e9f5089c11eb800a00710a24060e&dclid=CL72n4PEouwCFdMwuQYd9OIJTQ

Shipping on that one cap that I checked was almost $8.00?
I dunno if you can get the same ship price on all those caps, but I suspect you can.

These guys sell caps too, and the last time I checked you can get unlimited number for $5.00 ship
https://www.badcaps.net/index.php?pageid=master_list

If all those caps are old, your better off replacing them all because all electrolytic caps do have a limited life span

 

[ikonix360]

Sure I could have gotten a new supply, but I'm not one to just replace something when it only needs a few parts known to be higher failure items due to the cheaper quality of the parts used.

Now had they used the same brand for those two that they did for the four they might not have even been bad.

That said I suppose those two 6.3 volt caps were on the +5 volt circuit which is running them very close to max voltage. Could have contributed to their failure.

I ordered the 6 caps I needed.

Most often the caps on the output of the supply fail because they are under a lot more stress than the rest of the power supply caps.

I only use Mouser for things like capacitors due to the wide availability of various voltages, values ETC... Plus it's very easy to find the exact capacitor I want.

For switch mode power supplies I look for capacitors specifically rated for that type of use and I get the ones with the lowest ESR, highest ripple current, highest temperature and longest life.



I got the cables soldered and heat shrink covering all joints.

Used a couple old CD-ROM drives as a load and fired the supply up so I could check the voltages to make absolutely sure I have it wired right. Everything checked out good. I also checked the ripple voltage on all the outputs and there was minimal to no ripple.

So I'll do a brief test this afternoon as I feel confident the supply will be ok for a brief test.

 

[Joe C]

You have an oscilloscope to measure power supply ripple?
I think the max ripple you should get from a power supply is 50mv

 

[ikonix360]

I do.

At home I have several scopes (over 10 last count) of various ages with nothing newer than maybe early 90s, but at work I have much better equipment.

Measuring with a DMM all ripple was under 20mV. Will check with a scope to be sure.

Not sure how its working with those two bad caps, but it does work.

The caps will be here Friday then I'll install them at work Monday as its rather slow at work now and I have Metcal soldering equipment there.

Just about finished securing the wiring with lacing cord so it looks nice.

Can't take pictures at work so I'll take some when I get home

 

[ikonix360]

Doesn't really matter now, but I was wrong about the original motherboard connector of the power supply having just 20 pins.

It has 20 pins, but there's a slide on four pin connector with +5 +12 +3.3 and ground so it would actually be a 24 pin.

Now the power supply has been running the last 20 minutes with two CD drives and one old hard drive without issue. Not much of a load, but at least it's something.

If it works with the PC and doesn't blow out hot air I'll leave it as is and just replace the caps. Otherwise I will need to speed up the fan which could be done by replacing the temp sensor (if it is a resistor) by a variable resistor or just wiring the fan to +5 Vdc or maybe to the +12vdc and +5Vdc which would give +7 Vdc to the fan.

 

[ikonix360]

The computer works with the power supply.

I am well pleased.

 

[Joe C]

Enjoy that 13yr old power supply!