mockingbird wrote on 2021-10-14, 13:40:

AppleSauce wrote on 2021-10-14, 13:26:

Generally speaking from what i gather on the psu, the esr meter seems to say that anything with a UF in the hundreds or thousands are low esr and the and anything less than that is just general purpose caps??
Does that sound right?

Bigger caps have lower ESRs by the nature of their manufacture (don't ask me to explain why - Better ask Wester547 over at badcaps)... So while it's normal to have something like a 5mm 10uF cap test at between 1 to 5 Ohms, 1 Ohm on something like a 10x20mm cap would be greatly suspect.

Keep in mind with the ESR meter that some of the caps you're replacing might test fine, but you don't test for other things with it like leakage current for example, so it's best to replace everything.

The meter does show Vloss , would that be leakage?

mockingbird wrote on 2021-10-14, 13:19:

There's no need at all to worry about lead spacing for any of these parts.

Ok, I just saw that the legs on those B suffix parts are bent out (e.g. on the 16V 100uF part) to give a 5mm spacing from the 2mm spacing leaving the rubber plug, and I don't like having to bend legs around too much. I once had to fit some capacitors with a different lead spacing to the PCB and wasn't happy how the capacitor couldn't fit close to the PCB, which left a relatively heavy component wobbling on its legs. Plus it looked untidy and left the cap sitting too high (heatsink clash), so I swapped those out when I could and have always checked lead spacing and dimensions since. I did see a nice motherboard feature where it had 3 holes for the large electrolytics, which allowed for 2 possible lead spacings and made life easier.

AppleSauce wrote on 2021-10-14, 13:47:

The meter does show Vloss , would that be leakage?

I don't know sir, I'm going to defer to the experts on that one. I have one of those meters, it's the inexpensive $20 microcontroller meters, correct? I have also seen Adrian Black comment on another important reading on his LCR meter (can't remember the acronym).

snufkin wrote on 2021-10-14, 14:03:

Ok, I just saw that the legs on those B suffix parts are bent out (e.g. on the 16V 100uF part) to give a 5mm spacing from the 2mm spacing leaving the rubber plug, and I don't like having to bend legs around too much.

I don't want to be disputatious, but I have never found that to be any problem whatsoever. You just take needlenose pliers, position the bend as close to the base, then clamp down and it straightens the lead. If you need to bend the lead for a wider lead spacing, then that's no problem either.

mockingbird wrote on 2021-10-14, 14:24:

I don't know sir, I'm going to defer to the experts on that one. I have one of those meters, it's the inexpensive $20 microcont […]
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AppleSauce wrote on 2021-10-14, 13:47:

The meter does show Vloss , would that be leakage?

I don't know sir, I'm going to defer to the experts on that one. I have one of those meters, it's the inexpensive $20 microcontroller meters, correct? I have also seen Adrian Black comment on another important reading on his LCR meter (can't remember the acronym).

snufkin wrote on 2021-10-14, 14:03:

Ok, I just saw that the legs on those B suffix parts are bent out (e.g. on the 16V 100uF part) to give a 5mm spacing from the 2mm spacing leaving the rubber plug, and I don't like having to bend legs around too much.

I don't want to be disputatious, but I have never found that to be any problem whatsoever. You just take needlenose pliers, position the bend as close to the base, then clamp down and it straightens the lead. If you need to bend the lead for a wider lead spacing, then that's no problem either.

Yeah one of these

https://badcaps.net/forum/showthread.php?t=50531
Badcaps seems to mention Vloss having some kind of relation to leakage.

Anywho should i go all low esr on the psu , or should I try and match the original caps or should I just get regular caps?

AppleSauce wrote on 2021-10-14, 15:32:

Anywho should i go all low esr on the psu , or should I try and match the original caps or should I just get regular caps?

Yes, use the same series you used for the motherboard for the PSU as well.

For 10V capacitors on the secondary, you can use 6.3V caps if you can't find it in 10V and vice versa (these are for the 5V rail). For 16V caps on the 12V rail, use 16V or higher.

You can go up in capacitance if you can't find the exact part.

mockingbird wrote on 2021-10-14, 15:46:

Yes, use the same series you used for the motherboard for the PSU as well. […]
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AppleSauce wrote on 2021-10-14, 15:32:

Anywho should i go all low esr on the psu , or should I try and match the original caps or should I just get regular caps?

Yes, use the same series you used for the motherboard for the PSU as well.

For 10V capacitors on the secondary, you can use 6.3V caps if you can't find it in 10V and vice versa (these are for the 5V rail). For 16V caps on the 12V rail, use 16V or higher.

You can go up in capacitance if you can't find the exact part.

Okay cool ill make a list then , one other thing for the motherboard could I possibly just twist the caps off with a pair of pliers or is this unsafe for a multi layer pcb?

AppleSauce wrote on 2021-10-14, 16:15:

Okay cool ill make a list then , one other thing for the motherboard could I possibly just twist the caps off with a pair of pliers or is this unsafe for a multi layer pcb?

If you have no experience re-capping motherboards, then you will destroy the board... This is an acquired skill sir, there is no nice way of saying that. Definitely do not twist off the caps. You will tear out the via, and rip up traces attached to it. I know you've read that this is done with SMD caps, but that is something completely different and will absolutely not work here.

What kind of equipment do you have?

Hey AppleSauce, I looked through my stash and I found a model that matched your criteria.

It's the Dell NPS-250KB B Rev 02.

1) Mostly Japanese capacitors (Rubycon YXG, Nichicon PW), and the rest are Taicons, which can be hit and miss, but should be ok
2) IC driven 5VSB design (that's the daughterboard you see covered in yellow tape in the primary section)

This is Dell branded, but I checked the pinout and it's standard ATX, so not proprietaty.

The only thing you may not like is that it has no power switch on the back.

There are 5 molex connectors and one floppy connector. There's also a P4 connector. The manufacturing datecode is early 2002.

mockingbird wrote on 2021-10-14, 16:43:

AppleSauce wrote on 2021-10-14, 16:15:

Okay cool ill make a list then , one other thing for the motherboard could I possibly just twist the caps off with a pair of pliers or is this unsafe for a multi layer pcb?

If you have no experience re-capping motherboards, then you will destroy the board... This is an acquired skill sir, there is no nice way of saying that. Definitely do not twist off the caps. You will tear out the via, and rip up traces attached to it. I know you've read that this is done with SMD caps, but that is something completely different and will absolutely not work here.

What kind of equipment do you have?

Relax i only twisted a cap off the psu that was being stubborn , it was under a crapton of solder , the traces seem fine , the legs are still on the pcb. I was asking since motherboards seem more delicate than psus.
I guess I won't be doing it with the motherboard then.

mockingbird wrote on 2021-10-14, 20:34:

Hey AppleSauce, I looked through my stash and I found a model that matched your criteria. […]
Show full quote

Hey AppleSauce, I looked through my stash and I found a model that matched your criteria.

It's the Dell NPS-250KB B Rev 02.

1) Mostly Japanese capacitors (Rubycon YXG, Nichicon PW), and the rest are Taicons, which can be hit and miss, but should be ok
2) IC driven 5VSB design (that's the daughterboard you see covered in yellow tape in the primary section)

This is Dell branded, but I checked the pinout and it's standard ATX, so not proprietaty.

The only thing you may not like is that it has no power switch on the back.

There are 5 molex connectors and one floppy connector. There's also a P4 connector. The manufacturing datecode is early 2002.

Are you sure that's going to be enough for a fully kitted out pentium 3 @450 mhz?

I'm going to be using canopus spectra 256 ddr , a tseng labs et6100 , 2 voodoo 2s in sli , a sound blaster live , a diamond monster mx300 and creative drx2 decoder card plus a cd and DVD drive and a floppy drive plus a mechanical hdd.

AppleSauce wrote on 2021-10-15, 02:11:

Relax i only twisted a cap off the psu that was being stubborn , it was under a crapton of solder , the traces seem fine , the legs are still on the pcb. I was asking since motherboards seem more delicate than psus.
I guess I won't be doing it with the motherboard then.

All I'm saying is you will be in for a surprise when you start working on the motherboard... Mark my word. If I were you I'd practice on a motherboard you don't care about before you proceed.

Are you sure that's going to be enough for a fully kitted out pentium 3 @450 mhz?

I'm going to be using canopus spectra 256 ddr , a tseng labs et6100 , 2 voodoo 2s in sli , a sound blaster live , a diamond monster mx300 and creative drx2 decoder card plus a cd and DVD drive and a floppy drive plus a mechanical hdd.

Absolutely... And you won't even be close to reaching 250W.

People who really rode these old PSUs hard were those with several 10K SCSI HDDs, those can draw a lot of power.

I'd be surprised if you even reached 150W with that setup.

If ya reckon its enough I'll buy one , but what am I going to do about the motherboard caps ?

For mouser you need a minimum 60 dollar order and the caps for the motherboard come out at about 20 aud. So I'd be wasting 4o aud on shipping.

Are there any other places I could get the caps that are reputable and don't have crazy high shipping fees?

AppleSauce wrote on 2021-10-15, 04:05:

If ya reckon its enough I'll buy one , but what am I going to do about the motherboard caps ?

For mouser you need a minimum 60 dollar order and the caps for the motherboard come out at about 20 aud. So I'd be wasting 4o aud on shipping.

Are there any other places I could get the caps that are reputable and don't have crazy high shipping fees?

I have a guy you can buy caps from, PM me for details sir.