"POWER PC" ML915 350W power supply

[c_hegge]

Re: "POWER PC" ML915 350W power supply

KDC are even worse on the primary side than Fuhjyyu. Every single time I see them, they are bloated, even on PSUs without APFC.

[momaka]

Re: "POWER PC" ML915 350W power supply

I guess I'll go against the flow and say just leave the big caps on the primary side alone (at least for now). This PSU doesn't have an APFC circuit, so it doesn't really stress them that much at all. I have 10+ -year old L&C PSU with CapXon KMs on the primary - still works fine. Those large caps just don't fail that often (APFC circuits aside, of course). If the voltages are stable when the PSU is under high load, just leave them.

[Shocker]

Re: "POWER PC" ML915 350W power supply

Yes I'm sure for mine; when I was rebuilding it I was reflowing some of the solder joints on it and did the primary caps, and their leads didn't feel like the ones that snap-in caps have (felt like regular leads).

If you look at the PCB underside photos I posted on the first page of this thread, at the primary cap section you can see a hole that the solder did not cover and it is of normal lead size, not snap-in.

The open holes are for caps with 7.5mm lead spacing. All snap-in caps have 10mm spacing. Remove the original primary caps and look at the top of the board.

[Newbie2]

Re: "POWER PC" ML915 350W power supply

And are you absolutely 100% sure that the holes are too small???

Yes I'm sure for mine; when I was rebuilding it I was reflowing some of the solder joints on it and did the primary caps, and their leads didn't feel like the ones that snap-in caps have (felt like regular leads).

If you look at the PCB underside photos I posted on the first page of this thread, at the primary cap section you can see a hole that the solder did not cover and it is of normal lead size, not snap-in.

[Shocker]

Re: "POWER PC" ML915 350W power supply

And are you absolutely 100% sure that the holes are too small???

[c_hegge]

Re: "POWER PC" ML915 350W power supply

Th3_uN1Qu3 is right. I have done it with a Linkworld. I used a screwdriver to widen the holes.

I use either that or the soldering iron tip

[Newbie2]

Re: "POWER PC" ML915 350W power supply

I see. Still, even though snap-ins rated at 560uf 200V are slightly cheaper than the regular Chemicons on Digikey.ca, for me after shipping and taxes it'll still cost around $16-$17. If I had the money to waste, I'd rather spend the extra $2 and get the Chemicons with regular leads so I don't have to touch the PCB.

I'm not going to use my old dead Enermax's PCE-TUR caps. They're pretty old so I doubt they're in good shape.

[Shocker]

Re: "POWER PC" ML915 350W power supply

Another option perhaps would be to use a round file (if the holes are spaced 10mm). Just a suggestion.

[goodpsusearch]

Re: "POWER PC" ML915 350W power supply

Th3_uN1Qu3 is right. I have done it with a Linkworld. I used a screwdriver to widen the holes.

[Th3_uN1Qu3]

Re: "POWER PC" ML915 350W power supply

It's very hard to damage them with drilling as well. Drill from the side with the traces and everything will be fine.

[Shocker]

Re: "POWER PC" ML915 350W power supply

It's hard to see how you could damage the pads for the primary caps since you have successfully replaced the 12v secondary rectifier which is in TO-220 and far more difficult to solder than those big primary caps.

He means damaging them by drilling them out to fit snap-in caps. It's very hard to damage those when soldering.

[Th3_uN1Qu3]

Re: "POWER PC" ML915 350W power supply

It's hard to see how you could damage the pads for the primary caps since you have successfully replaced the 12v secondary rectifier which is in TO-220 and far more difficult to solder than those big primary caps.

[Shocker]

Re: "POWER PC" ML915 350W power supply

This was the Enermax that I had recapped the secondary side in the past. I recapped that PSU because the issue was able to power on but it somehow could no longer reliably power a P4 3.2GHz Prescott PC that I had, since that PC kept freezing when a game (like Call of Duty 4) or anything intensive was run on it. Unfortunately replacing all the secondary side caps did not fix that issue, and I soon took it out of service. It was replaced by my (then newly) rebuilt Delta Power 450W, which solved all the issues with the PC, and the Delta Power 450W reliably powered that PC until I gave the PC's parts to my relatives (I kept my PSU).

I used the Enermax for scrap parts, and it was where I got the two Y caps for this POWER PC PSU. I also took the 2700uf 16V Panasonic FM caps I used out of the Enermax for this cheap PSU as well, since I had none leftover and those caps weren't used for very long.

I will not try to fix that old Enermax, as it is ancient and only has a 20-pin ATX connector. All the PCs in my house right now need the 20+4-pin ATX connector for their 24-pin motherboards, so this Enermax is of no use to me if it worked.

It would be interesting to find out the problem with the Enermax. But, still, if you're dead set on the PSU in the thread, I don't care.

Well if I took the risk and the solder pads came out damaged, I would lose a $23 CAD PSU plus the work I put into it to upgrade its internal components. Wasting almost $20 CAD on new primary caps seems like the better option if I had to pick either one.

They are only 85°C caps, mind you. Chemi-con also has a PAG series which is 105°C and includes a 560uF 200V 18mm. It also has a higher ripple rating and lower dissipation factor, so if you can get it at a reasonable price, go for it. If the PCB doesn't have 7.5mm hole spacing, you can always bend the capacitor leads outwards and mount them a few mm off the board.

[Newbie2]

Re: "POWER PC" ML915 350W power supply

It's not the same Enermax you recapped, is it??? If so, try new primary caps and see if they fix the problem.

This was the Enermax that I had recapped the secondary side in the past. I recapped that PSU because the issue was able to power on but it somehow could no longer reliably power a P4 3.2GHz Prescott PC that I had, since that PC kept freezing when a game (like Call of Duty 4) or anything intensive was run on it. Unfortunately replacing all the secondary side caps did not fix that issue, and I soon took it out of service. It was replaced by my (then newly) rebuilt Delta Power 450W, which solved all the issues with the PC, and the Delta Power 450W reliably powered that PC until I gave the PC's parts to my relatives (I kept my PSU).

I used the Enermax for scrap parts, and it was where I got the two Y caps for this POWER PC PSU. I also took the 2700uf 16V Panasonic FM caps I used out of the Enermax for this cheap PSU as well, since I had none leftover and those caps weren't used for very long.

I will not try to fix that old Enermax, as it is ancient and only has a 20-pin ATX connector. All the PCs in my house right now need the 20+4-pin ATX connector for their 24-pin motherboards, so this Enermax is of no use to me if it worked.

Yes, I understood the risk of damaging the solder pads. But it's your choice: waste $$$ on the aforementioned Chemi-cons or take the risk.

Well if I took the risk and the solder pads came out damaged, I would lose a $23 CAD PSU plus the work I put into it to upgrade its internal components. Wasting almost $20 CAD on new primary caps seems like the better option if I had to pick either one.

[Shocker]

Re: "POWER PC" ML915 350W power supply

I do have two old PCE-TUR 680uf 200V caps in a dead Enermax EG301P-VE PSU that I have, however I'm afraid that I might damage the solder pads on the POWER PC PSU PCB if I try to enlarge them for radial snap-in caps. I don't know if the PCE-TUR caps would be too good, with that dead Enermax being almost a decade old plus the PCE-TUR brand.

Those "PCE-TUR" caps (the actual company is CEC) are not a good brand. I'd save up for good caps. It's not the same Enermax you recapped, is it??? If so, try new primary caps and see if they fix the problem.

Yes, I understood the risk of damaging the solder pads. But it's your choice: waste $$$ on the aforementioned Chemi-cons or take the risk.

[Shocker]

Re: "POWER PC" ML915 350W power supply

The STTH2002CT has significantly lower forward voltage which means higher efficiency - less heat.

Mind you, a Schottky rectifier would be better still. But I agree, not worth buying new parts for this POS. Still, if you come across a suitable Schottky (60V min, 100V preferred), go ahead and put it in.

[Newbie2]

Re: "POWER PC" ML915 350W power supply

I do have two old PCE-TUR 680uf 200V caps in a dead Enermax EG301P-VE PSU that I have, however I'm afraid that I might damage the solder pads on the POWER PC PSU PCB if I try to enlarge them for radial snap-in caps. I don't know if the PCE-TUR caps would be too good, with that dead Enermax being almost a decade old plus the PCE-TUR brand.

[Shocker]

Re: "POWER PC" ML915 350W power supply

That makes perfect sense to replace the stock KDC primary capacitors, however for me getting two 560uf 200V caps (that aren't the common snap-in type) would be expensive. United Chemicon 560uf 200V SMG series capacitors go for $4.62 CAD a piece on Digikey.ca, and getting two of those ($9.24 CAD) along with paying for $8.00 shipping and ridiculous 15% sales tax (in my province of Canada) would bring an order total to $19.83 CAD (for about $10 worth of caps!).

Ever thought of enlarging the PCB holes???

[Scenic]

Re: "POWER PC" ML915 350W power supply

No old/dead PSUs to rip caps out of..?

[Newbie2]

Re: "POWER PC" ML915 350W power supply

I often run into the sky 550W (like the one I mentioned) with bloated KDC primary caps. I would probably replace them with some good 105*C rated ones.

That makes perfect sense to replace the stock KDC primary capacitors, however for me getting two 560uf 200V caps (that aren't the common snap-in type) would be expensive. United Chemicon 560uf 200V SMG series capacitors go for $4.62 CAD a piece on Digikey.ca, and getting two of those ($9.24 CAD) along with paying for $8.00 shipping and ridiculous 15% sales tax (in my province of Canada) would bring an order total to $19.83 CAD (for about $10 worth of caps!).

I spent a total of $23 CAD on this PSU ($20 + 15% sales tax) and spending another $19.83 on it would bring that to $42.83 CAD total, which I feel isn't worth it. With just over $40 CAD, here I could purchase a decent not-so-gutless power supply, or even a good well-built power supply that's on sale.

I know I spent some serious money rebuilding my Delta Power 450W, however I don't have so much money to waste these days. This POWER PC PSU won't be used much if at all by me, so I just wanted to do whatever I could with it provided the parts I had. I would most definitely replace the KDC primary caps with good replacements if I could, however the cost for me doing so currently isn't justifiable considering the PSU not being actively used right now.