Are these caps bad?

[epikcap]

I have a few pictures of my motherboard that crapped out about half a year ago. The CPU is still good and so is the RAM. If I could get replacement caps and everything done for ~$15-20, I think it'd be worth it.

Here are some pictures of the caps I think might be bad. I don't want to replace the other ones, even though they're of inferior quality, if I don't have to.

There are no obvious leaks, but the tops are slightly bulged.

Top-down:


Side:


Single:


Three:


Close-up of two of the three:


Thanks!

[Wizard]

Re: Are these caps bad?

Ost! Ew. They may be bad, but what is the problem with this system? Certain you have good PSU, clean heatsink, quality memory (IMPORTANT!) and good video card?

VIA chipset on a cheap board is notorious for problems.

Cheers, Wizard

[Scenic]

Re: Are these caps bad?

mhh.. seeing those pics..

looks like an ECS board... so the new caps would be worth more than the board *lol*

[PCBONEZ]

Re: Are these caps bad?

Yes they -might- be bad.
Ost will go bad without showing it.

[epikcap]

Re: Are these caps bad?

Ost! Ew. They may be bad, but what is the problem with this system? Certain you have good PSU, clean heatsink, quality memory (IMPORTANT!) and good video card?

VIA chipset on a cheap board is notorious for problems.

Cheers, Wizard

Hey Wizard,

The board will sometimes POST, more often not, and when it does POST, I'll get random BSODs.

Yes, I've tried the PSU, RAM, and video card on another system and all work perfectly. I've cleaned off the thermal grease on the heatsink and reseated the CPU with new thermal compound to no avail.

And yes, it's an ECS motherboard. I just wanted a cheap solution to fixing this rig. $20 for some new caps is better than buying a new motherboard for an outdated (2.4ghz, single core) CPU. And at the moment, there's just simply no budget for a new computer.

Those OST caps are 6.3V 3300uF so I was thinking of picking up Rubycon MBZ Low ESR capacitors with the same specifications, 3300uF 6.3v, 10mm wide to replace them with...does that sound alright?

Thanks!

[PCBONEZ]

Re: Are these caps bad?

It's not obsolete if it's still useful and gets the job done well enough.
I'm not gonna replace my electric can opener just because someone is making one that opens cans faster.

MBZ is perfect replacement for those Ost.

There should be some 16v caps.
What are those?

.

[epikcap]

Re: Are these caps bad?

The MBZ are of the same rating as the OST...3300uF and 6.3V.

[PCBONEZ]

Re: Are these caps bad?

I'll try again slower.

There
should
be
some
16v
caps.

-What- -are- -those-?
.

[Toasty]

Re: Are these caps bad?



You're BAD !!

[epikcap]

Re: Are these caps bad?

rofl. I admit it. I read too fast.

There are 10V and 25V both of which are G-Luxon...I can't seem to find any 16V caps, but basically, every cap that's not OST is G-Luxon.

[PCBONEZ]

Re: Are these caps bad?

Your processor VRM has a high side and a low side.
On a P4 (or comparable AMD) the high side will be on +12v power and 6.3v caps would blow there pretty darned quick.
The last two pics appear to be of the VRM high side caps.
-
You may have a non-compliant board too where the CPU is powered by +5v instead of +12v. It's not like that's never happened. Just not too often.

Voltages on a mobo are +12v +5v and +3.3v
Volts rating of the caps needs to be equal to or greater than the voltage they are on.

10v and 6.3v rated caps can be used interchangeably because you know neither is on +12v and either will work on both +5v and +3.3v.
[This rule does not apply to things that aren't motherboards. If it's not a motherboard check the voltages with a meter before switching to lower volt rated caps.]

.

[linuxguru]

Re: Are these caps bad?

G-Luxons are much worse than OSTs - hopefully, none of those are in VRM or any other high ripple-current location. I'd replace every G-Luxon of value greater than or equal to 470 uF.

[epikcap]

Re: Are these caps bad?

G-Luxons are much worse than OSTs - hopefully, none of those are in VRM or any other high ripple-current location. I'd replace every G-Luxon of value greater than or equal to 470 uF.

Looks like I have to replace every single cap then.

[epikcap]

Re: Are these caps bad?

Your processor VRM has a high side and a low side.
On a P4 (or comparable AMD) the high side will be on +12v power and 6.3v caps would blow there pretty darned quick.
The last two pics appear to be of the VRM high side caps.
-
You may have a non-compliant board too where the CPU is powered by +5v instead of +12v. It's not like that's never happened. Just not too often.

Voltages on a mobo are +12v +5v and +3.3v
Volts rating of the caps needs to be equal to or greater than the voltage they are on.

10v and 6.3v rated caps can be used interchangeably because you know neither is on +12v and either will work on both +5v and +3.3v.
[This rule does not apply to things that aren't motherboards. If it's not a motherboard check the voltages with a meter before switching to lower volt rated caps.]

.

Basically, the safest way is to replace all the caps with 16V caps with the same uF value...?

Or should I replace those with the slight bulge and proceed from there?

[PCBONEZ]

Re: Are these caps bad?

Dead board with OST and G-Luxon.
Even if only some are bad the others aren't far behind.
Best thing is to replace all of them.

Yes 16v caps need to be replaced with at least 16v.

As I can't see what's there the 25v may or may not be on +12v and should also be at least 16v caps.
Sometimes they over-volt small caps just because they connect to things outside the case. (sound, lan, usb, ect). Other times they are on +12v for the fan power.
.

[epikcap]

Re: Are these caps bad?

Well, I've managed to replace most of the larger caps on the board that I could easily source. There's still a handful left that haven't been replaced. I'm looking for them as we speak.

Good news: The board will boot again!

Bad news: Once the system gets sufficiently warm, the board will refuse to boot until it cools down a little bit. And by sufficiently warm, I mean ~38*C or so for the CPU and power temperatures.

Is the problem getting the motherboard to POST when it's warmer possibly due to more bad capacitors in what I have yet to replace?

[epikcap]

Re: Are these caps bad?

Seems like even when it's cool, the board still won't boot. Guess there's more caps to replace, huh?

For what it's worth, if the machine is on, it's stable (from what short testing I've done), and all warm starts (reboots) work perfectly. It's just the cold start that's giving it problems. Does that narrow down the problem?

[PCBONEZ]

Re: Are these caps bad?

Try with a different power supply and see if it changes.

[epikcap]

Re: Are these caps bad?

Try with a different power supply and see if it changes.

Well, yesterday I plugged in a different, reliable power supply which seemed to fix the problem. I thought all was going well so I ran Prime95 for 26 hours to make sure everything was OK, and the test passed flawlessly.

After turning off the computer and moving it to where I finally want it, I turn it back on, and lo and behold, no POST. But it ran Prime95's torture test fine...any suggestions?

Thanks.

[lucky13]

Re: Are these caps bad?

Well, I've managed to replace most of the larger caps on the board that I could easily source. There's still a handful left that haven't been replaced. I'm looking for them as we speak.

....

Is the problem getting the motherboard to POST when it's warmer possibly due to more bad capacitors in what I have yet to replace?

So which caps that should be replaced have not been replaced yet?