Recapping GA-M55plus-S3G using lower rated capacitance

[rhan101277]

My computer has failed for about a week now. I tried power supply replacement after finding that my computer would turn on then immediately off.

After more troubleshooting and removing peripherals, I found that the computer would not stay on with the 12V ATX 4pin connected. My capacitors were bulging and they were shorted.

I replaced (5) 3300uF capacitors 6.3V rating

with

(3) 1,000uF capacitors 10V rating
(2) 1,000uF capacitors 16V rating

While I know decreasing the capacitance is not recommended my computer has been stable for an hour. I plan on getting a new mobo, CPU barebones at the end of next month.

Less capacitance means less time that the capacitor can hold the charge, these ones are meant to keep the power going to the CPU stable correct?

I have a degree in electronics but it has been so long since I have had to use any of those skills.

What exactly can using a lower capacitance rating do?

Not be able to supply voltage for a certain duration when its needed?

Discharges to fast?

Any help would be appreciated, I have a decent back ground, but most I have learned about caps were how they worked in power supplies to reduce ripple.

[Th3_uN1Qu3]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

There is a large chance that they used so high capacitance values just to get the required ESR. Capacitor technology has progressed a lot in the past few years. If the board runs fine there's nothing to worry about.

[Scenic]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

just for reference..
http://bambooz.pytalhost.net/badcaps/M55Plus-S3G.jpg

those 5 caps you mentioned seem to be on the CPU VRM output (the 5 black ones with the X vent above the CPU socket)

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

just for reference..
http://bambooz.pytalhost.net/badcaps/M55Plus-S3G.jpg

those 5 caps you mentioned seem to be on the CPU VRM output (the 5 black ones with the X vent above the CPU socket)

Those are the five I had to replace. So they don't help control Vcore? edit: I think I figured it out, they smooth out the Vcore and they are in parallel

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

Also i was thinking from school that capacitors that are in parallel add up, like resistors in series do. I remember that being different

[Uranium-235]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I am concerned with that much difference

you're replacing 16500uf with 5000. that bothers me. but if it works fine, it might continue to, for now

[PCBONEZ]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

Bulk capacitance is for smoothing transients but that is -NOT- why they used 3300uF caps there.

They used those caps for low ESR and high Ripple ratings.

It's doubtful 1000uF caps have low enough ESR to remove the ripple [means possible unstable system, reboots, BSOD, corrupted data, etc.] and also doubtful they have high enough of a ripple rating to not overheat. [means very short life for the caps.]
.

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

Well it is just a quick fix. These caps came from a spare PC power supply I have so they should be good for ripple and heat.

6 hours uptime now, with graphics intensive games occasionally. I am going to order the proper size.

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I find these caps are made by <BH>, maybe made in china. I can't find any accurate specs on them. I am going to order some rubycons from here on Friday.

[Th3_uN1Qu3]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I find these caps are made by <BH>, maybe made in china. I can't find any accurate specs on them.

There's a good reason why you can't find specs. They won't last long. I thought you used better ones.

I am going to order some rubycons from here on Friday.

Good idea.

[Rulycat]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I find these caps are made by <BH>, maybe made in china. I can't find any accurate specs on them. I am going to order some rubycons from here on Friday.

I remember seeing some BH caps in a CIT PSU. It was £16 which kind of tells you how good those capacitors are.

[PCBONEZ]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

BH is properly BH Pro-An. They are rebadged KOME brand.
Both made by Pro-An Electric Co. out of Hong Kong.
http://www.proan.com.hk/index.php?op...d=62&Itemid=76
.
And yes, they are crap..
.

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I am not sure if these are 10mm tall or 25mm, the 3300uF Rubycon only come in 25mm tall.

[Per Hansson]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

A 3300uF cap must be tall, atleast 25mm if only 10mm thick
Just measure it but in the picture linked by Scenic they look to be 25mm tall to me.
I borrowed this pic from Newegg, seems that 25mm is correct.
Anything is ok so long as it clears the heatsink you use...

Btw, I'm surprised the thing works at all with the caps you put in, for sure it will not have a long life before it cooks those poor capacitors

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

24hr no cooking yet, still getting correct ones though

[rhan101277]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

Replaced the five short term fix capactors with.

Nichicon HZ 6.3v 3300uF 10X25mm - Ultra low ESR

Nichicon Part number: UHZ0J332MPM

Rated Voltage: 6.3v

Rated Capacitance: 3300uF

Capacitance Tolerance: 20%

Temperature Range: -25 to 105C

Rated Ripple Current: 4690

Diameter: 10mm

Height: 25mm

[PCBONEZ]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

Congrats!

You are now allowed to have a warm fuzzy.
.

[zooma.tech]

Re: Recapping GA-M55plus-S3G using lower rated capacitance


check this circuit in the photo , and remind the 3 channel are the same
*substitute the same values of components

[luke10050]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

wait that means instead of using 5x3300uF caps you could use 2800uF caps with similar ratings with the sixth one in?

[tmiha71]

Re: Recapping GA-M55plus-S3G using lower rated capacitance

I replaced (5) 3300uF capacitors 6.3V rating

with

(3) 1,000uF capacitors 10V rating
(2) 1,000uF capacitors 16V rating

When you had improvements with this low capacitance caps, and higher ESR than original (dead), you should continue to try to poly mod that board :-))...

Keep that capacitance, and lower ESR, something 820uF, or 1000uF from any manufacturer...

Only suggestion :-))... /Accept for to late advice../

Note about PSU caps, usually they're at least one notch better, or at least should be, than mobo caps - they're alone, and sometimes they had to swallow more than 10A...