Caps choice

[Drack]

Hi guys, this PSU is working ok right now, I changed the "470" for the biggest caps that fit, supposedly a 560uf but I think they are 470, I want to change the caps but I only have kze 1500uf for 3.3v and 5v or TK 3300uf for those, and FM 1000 or 1200uf for 12v don't remember which, or TK 1800uf the trouble is that this are low ESR caps and that TK is not a good brand but this where on a dead Mobo that worked with them for a couple years without trouble but then my dad dropped it and it died
I only need 150w from this PC so this should work.
I can put the FM on the place where the small caps are(470) and the TK and kze on place of the 1000

[Pentium4]

Re: Caps choice

Don't use the TK caps. They'd probably throw the whole feedback loop out of whack. KZE are great for PSU. FM should be okay on the 12V since the ESR isn't that high at 1200uF, although that is pretty low capacitance for the most important rail. You don't have anything else available?

[Drack]

Re: Caps choice

No, I think I can put 2 FM's for 12v but that's all, it would be better than the 1000uf and 470uf that are there the tks are too low ESR right?

[Drack]

Re: Caps choice

Someone?

[Drack]

Re: Caps choice

Now the PSU will turn off after a while of use, this was on a core 2 duo PC for 5 years, (thanks solid caps on Mobo)and it was working ok but I replaced anyway because of the cheap caps and put one exactly like this one but with more caps on secondary and new... The bad thing is that those are asiaX yep rebranded fuhjkyous, will change them when I have some money for something acceptable at least (samxon maybe, or the best I can find at the time) will ad line filtering and maybe put a bigger diode on 12v, I have some 30a schottky on the shelf or 20a, better than the 16a that is there

[SIDMX]

Re: Caps choice

...I only have kze 1500uf for 3.3v and 5v or TK 3300uf for those, and FM 1000 or 1200uf for 12v...I can put the FM on the place where the small caps are(470) and the TK and kze on place of the 1000

As Pentium 4 already said don't use those TK caps, there's no point in replacing unreliable Seacon caps with unreliable TK caps also the change in ESR/Impedance may be too drastic and may also affect the cutoff frequency of output filters, watching the datasheet the impedance ratings of those Seacon RS caps are really high (around 100mohm) so even KZE and/or FM may not be suitable for your PSU. I say if it is working and you have no other choice of caps better to leave it as it is for now until you get better quality caps.

Now the PSU will turn off after a while of use...

Put back the old caps and it should work ok if nothing else it's damaged...I guess

...one exactly like this one but with more caps on secondary and new... The bad thing is that those are asiaX yep rebranded fuhjkyous, will change them when I have some money for something acceptable at least (samxon maybe, or the best I can find at the time) will ad line filtering and maybe put a bigger diode on 12v, I have some 30a schottky on the shelf or 20a, better than the 16a that is there

Same suggestion: leave it as it is until you get the caps, adding the line filter and changing the 12V rectifier may be a waste of time/money IMO unless you already got the parts or can savage them from old units, but if you really want to change the rectifier check and match if possible Reverse Voltage rating as this is a common mistake when replacing Fast Diodes with Schottky Diodes
Been there, done that...

[Drack]

Re: Caps choice

Already have the parts and the only cap I changed was the 2 bulk caps, didn't touch anything else...
Yep, p4 killed a schottky that way lol, I have one 20a 150v fast recovery, that should work

[Agent24]

Re: Caps choice

If it shuts off after a while something may be be going out of spec and the controller chip is shutting everything down. Possibly something is overheating, though I don't see any temperature protection on it.

What happens if you turn it on again straight after it shuts down? Will it run for the same time or shut off again quickly? That would imply overheating.

Like SIDMX said, might be worth putting the original capacitors back in and seeing if it runs normally again.

Maybe you could you measure heatsink temperature and voltages, and compare between old and new capacitors?

[Drack]

Re: Caps choice

I know it's not overheating It barely gets warm and I'm just drawing like 100w top, it just restart the PC like if power went out for half a second, made it with 2 different Mobo's so it's the PSU, other PSUs like this one made this a couple months before blowing the switching transistors.
Will change the caps and let you guys know what happens.

[Agent24]

Re: Caps choice

First thought is if the capacitors were old and have dropped in capacitance, the transistors would have to work harder to keep the voltages up, would overheat, and eventually fail.

How are you determining temperature? I think you'd need to probe the heatsink with a thermocouple. Fan exhaust temperature may not tell you much, considering those heatsinks don't have many fins to actually dissipate heat into the air.

[Drack]

Re: Caps choice

Will change the caps and see, it's powering a socket 478 Celeron processor at 2.4ghz, no gfx one HDD and 2 sticks of RAM and that PSU used to work warmer on the core2duo so most be the caps and i don't have a thermocouple so only my hand will tell for now lol I was thinking on adding more line filtering ( i added the small PCB) but now I think just will leave it like that and just put the original caps

[momaka]

Re: Caps choice

I guess I am the only one here that might say this, but...

YES, DO use the highest capacitance caps you have that you can fit there, even if they are TK or some other crap brand. I only see a single PI coil on the output of this PSU (looks like the 12V rail), so the capacitance is even more important here than the ESR. Of course, if you can find high capacitance from a known good brand, that would be the best thing to do. Chemicon KZE is very good for PSU use.

Also, I see some heavily charred output wires from the minimum load resistors. So definitely make sure to remove those minimum load resistors. If the PSU is not happy, put a 20-40 Watt 12V halogen bulb on the 5V rail.

Lastly, if the PSU is shutting off or making your PC restart, check all of the solder joints and reflow any that look even slightly bit suspicious. Also add the input filtering if you have it. Without the input filter, any noise on the line input could easily travel through to the secondary side and cause the PC to restart and crash. Input filtering works both ways: it reduces EMI from the PSU and reduces outside noise from coming into the PSU. So it is rather important.

Another thing worth mentioning is that cheap PSUs are not a good idea when it comes to powering motherboards with SDRAM, since many mobos with SDRAM slots may take power for the RAM directly from the 3.3V rail. So if you are using this PSU to power an older board with SDRAM, that could well be the reason why the PC crashes.

[Drack]

Re: Caps choice

Hi momaka, I changed the input caps and took my wireless card out (some TP-LINK bitch that don't work on anything from ASRock Asus or Biostar and it's not damaged I used to have 3 of those and they were all like this one) and it seems to be working ok, I need some better caps for 12v but don't have money at the moment so it will have to wait for a bit, the kze are old(2004 I think), from an ASRock board that it's working wierd ( only recognize one ram stick and only half of it, and turns on for half a second turns off and then turns on like it should...) And put something crapier in that one, but that's off topic.
The TK are low ESR caps but they hold charge for days and make a big enough spark that is kind of blueish, I think this could make the PSU to put more ripple on because of the low ESR and this being tinned for higher esr, so I was thinking on putting one 1000uf FM for 12v and another cap with higher ESR in parallel (2200uf or more) the PC uses DDR so it's being regulated to bring it down to 2.5v and the filtering coil is for 3.3v and no space for adding more for the other rails, this PC might have the other PSU that I posted a while ago the green Agiler and my main PC would have something really better (thanks longbow) but again that's something for another thread

[momaka]

Re: Caps choice

The TK are low ESR caps but they hold charge for days and make a big enough spark that is kind of blueish, I think this could make the PSU to put more ripple on because of the low ESR

FM is also quite low ESR, so the difference between that and the TK probably isn't that significant, depending on which series of TK you have. If it's ATWY:
TK ATWY, 16 V, 1800 uF: 12 mOhms ESR, 2800 mA ripple current
Panasonic FM, 16 V, 1000 uF: 19 mOhms ESR, 2180 mA of ripple current

Really the only differnece between the TK and Panasonic is that Panasonic are good reliable caps, whereas the TK are not. But the increase in capacitance from 1000/1200 to 1800 uF should help quite a bit to bring the ripple down, especially since your PSU doesn't have any PI coil (other than the 3.3V rail).

So when in doubt, especially with cheap PSUs, always go for the higher capacitance cap. The only PSUs that I've seen that don't adhere to this are Sirtec units - some of those have two 10 mm cap spots for the 12V rail, but if you fill the second spot with a proper-size capacitor, the PSU becomes unstable and squeals. But that's the only PSU I've seen do that. Most others don't care about the ESR. I've partially recapped Deer, Bestec, LiteOn, and HiPro units with Nichicon HN caps, and they worked fine.

[Drack]

Re: Caps choice

Well, I have all the caps I need, will buy solder tomorrow because the one I have right now is crap, I also found a couple OST RLP 3300uf for 5 and 3.3 v, I trust more on OST than toshin kogyo and there where no FM's, they are FJ 6.3v and FL 16v

[Agent24]

Re: Caps choice

I don't know about Toshin Kogyo. But they do list their capacitor colours as "Blown" http://www.toshinkk.co.jp/en/product/alumi-k.html !!!
Are they dead when you buy them?

OST are pretty rubbish though, I wouldn't use them.

[Drack]

Re: Caps choice

RLP don't die as much as RLS or at least that's what I have read, TK are Taiwanese caps they tend to die, but there were some batches of those that are kind of acceptable and my caps are old but working ok

[Wester547]

Re: Caps choice

Toshin Kogyo is actually a Japanese company, but they do have a Taiwanese subsidiary (Taiwan Toshin Kogyo, yup, you could have told yourself that ). The only unreliable series from them AFAIK are ATWY and ATWB, possibly ATWT, all very low impedance series (especially the former two). OST on the whole is inconsistent, unreliable, and unpredictable due to poor QA. So it's hard to say which series is more or less reliable, but the quickest and most likely preggers from them seem to be the 1800μF 6.3V RLZ series and 680μF 4V RLA series on motherboards, no thanks to the Prescott/high-TDP LGA775 CPU coolers that blow droves of heat right across them. I think FM and KZE will work fine for the output of a SMPS (and as momaka said, for half-bridge PSUs, capacitance matters more than ESR on the secondary side), and would also reiterate the warning to avoid using TK ATWY and OST.

As for why the PSU in question doesn't work anymore... I also recommend checking for bad solder joints or maybe even bad rectifiers. Hopefully a recap cures all issues.

[Drack]

Re: Caps choice

I changed the input caps and took my wireless card out (some TP-LINK bitch that don't work on anything from ASRock Asus or Biostar and it's not damaged I used to have 3 of those and they were all like this one) and it seems to be working ok

I stressed tested the PC and is working fine, the caps are ATWY ...
The kze are 1500uf, that's why I was talking about the 3300uf from OST, the pannys are 1500uf just like the kze and 1000uf for 16v and the ATWY are 1800uf
Btw I said Taiwanese because they are made in Taiwan even if the company is Japanese.

[Wester547]

Re: Caps choice

I stressed tested the PC and is working fine, the caps are ATWY ...
The kze are 1500uf, that's why I was talking about the 3300uf from OST, the pannys are 1500uf just like the kze and 1000uf for 16v and the ATWY are 1800uf

Just keep an eye on the ATWY is all, they may not last much longer.

Btw I said Taiwanese because they are made in Taiwan even if the company is Japanese.

Yeah, but Chemi-con has a Taiwanese subsidiary known as Taiwan Chemi-con (which they own 100% of), but that doesn't make those Taiwan-produced caps Taiwanese because Chemi-con import all of their materials from Japan. TK I don't know, they claim to use high purity cathodic and anodic foil, but at least some of their materials are sourced from Chinese and Taiwanese manfacturers (Liton, subsidiary of Lelon, and CHIANG AN, etc).

Good to hear it's fixed at least.