Gaba 330u "400w"

[pdavid]

This thing won't start hooked up to a motherboard and drives. I know it belongs to the garbage where I found it, but I could use it for and old P3 1.2 pc.
Someone tinkered with it before, 5vsb caps and the 12V schottky was definately replaced.
5v standby and power good are present, but when I try to start it just gives a silent click, voltages go up to a few hundred milivolts and won't do anything.
I know this is and age old symptom, so aside recaping what is the best way to fix it? ...except throwing it out

[pdavid]

Re: Gaba 330u "400w"

20amp 12V schottky is shorted and two 10V and one 16V cap values below 600uf. I use yageo caps of the same values for replacement and now the psu works... so far.

Edit: After an hour the secondary heatsink became pretty damn hot. Voltges are fine, I just can't measure ripple at the moment.
For load I used a motherboard, 800 duron and 3 hdd.

[c_hegge]

Re: Gaba 330u "400w"

They do get hot. I've burned my fingers on PSU heat sinks lots of times.

[momaka]

Re: Gaba 330u "400w"

20amp 12V schottky is shorted and two 10V and one 16V cap values below 600uf. I use yageo caps of the same values for replacement and now the psu works... so far.

I don't think Yageo caps have anything low ESR. If they aren't then you need to change them. Otherwise, you'll be passing extra ripple and noise to the hardware you're powering, and this may damage it.
You need caps with ESR at least as low as Panasonic FC, Nichicon PM, and Chemicon LXY and LXZ. A grade higher than those is what most PSUs usually use.

Edit: After an hour the secondary heatsink became pretty damn hot. Voltges are fine, I just can't measure ripple at the moment.
For load I used a motherboard, 800 duron and 3 hdd.

What replacement part did you use for the 12v schottky? If it's a fast recovery diode rather than a schottky, then that can be part of the reason why the secondary heatsink is so hot.

[pdavid]

Re: Gaba 330u "400w"

I don't think Yageo caps have anything low ESR. If they aren't then you need to change them. Otherwise, you'll be passing extra ripple and noise to the hardware you're powering, and this may damage it.
You need caps with ESR at least as low as Panasonic FC, Nichicon PM, and Chemicon LXY and LXZ. A grade higher than those is what most PSUs usually use.


What replacement part did you use for the 12v schottky? If it's a fast recovery diode rather than a schottky, then that can be part of the reason why the secondary heatsink is so hot.

I have 6.3V Panasonic FC caps, but mostly Yageo SC, SY and Samxon GT, GF. I usually get these from several stores around, though we got similar stock at work but...
I used mbr2045ct schottky, same as the one that got shorted. The other rails look untouched.
Mbr3045ct for 5 Volt and 1545ct for the 3.3 Volt rail. I suspect originaly there was fast recovery diode for the 12V rectification. You never know with these generic psus. It was in the trash anyway.
There is this tiny M51957B ic used for protection. I haven't even noticed it first!

[370forlife]

Re: Gaba 330u "400w"

Yageo = Teapo. Same series even.

[c_hegge]

Re: Gaba 330u "400w"

Noooooooo. NEVER under ANY circumstances recap with teapo.

[pdavid]

Re: Gaba 330u "400w"

Noooooooo. NEVER under ANY circumstances recap with teapo.

Oh, come on! I would use better, but for this psu.
The other issue around here is diameter and Yageo caps cover most. We also have Capxon Su,scon Sumec Samwa, Hitano and Arcotronic caps available
I really have to try hard to find Ruby, Nippon or Nichicon in the right uF value. Also I don't want to order a hundred pieces every time.

[c_hegge]

Re: Gaba 330u "400w"

Ok, I'll forgive you.

I can get nichicon HE and Panny FC for only a few dollars for a total recap, so for me, it simply doesnt make sense to use anything worse than them. If I'm going to do a repair, I prefer to so it well, so I don't have to do it again in a few years time, but for an older PC, fine.

[370forlife]

Re: Gaba 330u "400w"

Honestly teapo isn't that bad, especially in psu's. I wouldn't worry about them.

[PCBONEZ]

Re: Gaba 330u "400w"

Yageo = Teapo. Same series even.

Yes, Yageo is Teapo's parent company.

[Evil Lurker]

Re: Gaba 330u "400w"

Honestly teapo isn't that bad, especially in psu's. I wouldn't worry about them.

I totally agree. I got some PSU pulled teapos with date codes circa 2004 and the esr still tests good on them... I will say that about every black wrappered SK series I have run up on (I think that is the right series) was bloated but the green ones seem to hold up pretty good.

Not every bit of hardware is worth Panny's IMO, and unfortunately the PSU in this thread isn't one of them. If it was me, I would chunk it, I highly doubt there is any way in hell that ancient PSU could even do 250+ watts much less 400.

[PCBONEZ]

Re: Gaba 330u "400w"

Teapo don't have a prefect record in PSUs but they are much better than most non-jap brands.

Teapos bad rep came mostly from 8mm and up used on mobos.
They [8mm and up] were used in droves by many mobo mfrs up until around 2004-ish but since then they don't show up much in those sizes on mobos.
.

[c_hegge]

Re: Gaba 330u "400w"

I know there are far worse brands out there, but IMO, repairs should always be done properly. IE, with good quality japanese capacitors, especially when they are as cheap as they are.

[370forlife]

Re: Gaba 330u "400w"

Just for those who are curious, this is a Shenzhen Tommade Electronics built power supply. :

http://www.tommade.com/product_list.asp?MID=267&TID=218

they're apparently pretty big, at least they talk big, owning " 10 sub
manufactories, Our products from computer case, Powersupply, speaker to raw materials such as transformer,cable,fan,speaker unit,wooden box..."

http://www.tommade.com/about_company.asp