Dell Dimension 4700 with a blown cap

[smalltownguy]

So I'm blowing the dust out of a Dimension 4700 at work today when I notice that one of the capacitors near the memory area of the motherboard is blown. Totally blown. Goop on top and bottom of the cap.

The thing is, this PC SEEMS to be functioning properly. I've not gotten any reports of any malfunctions from the user.

So do I replace the cap? The machine works now - I kinda hate to futz with it in case I do more damage than good. Don't get me wrong, I'm skilled enough to replace the cap no problem - I've done it before.

What do you think? Do I fix what's (not) broke?

[Evil Lurker]

Re: Dell Dimension 4700 with a blown cap

Yes the entire motherboard should be recapped, and probably the PSU needs it as well.

And also the machine should NOT be turned on until such repairs have been completed.

Whoever the machine belongs to should be thankful that the problem was caught before any serious damage was done.

[PCBONEZ]

Re: Dell Dimension 4700 with a blown cap

The user probably is having problems but thinks it's software, RAM or the HDD.
Bad cap in RAM = Corrupted Data.
.
What you need to replace depends on what you have.
That varies from board to board.
The Polymers won't need replaced.
The 4 & 5 mm don't usually need replaced.
.
Can tell you more if you will provide the make and series of the blown cap.
.

[smalltownguy]

Re: Dell Dimension 4700 with a blown cap

Attached is a picture of the bad cap. It's a 2200uf 6.3 volt, but I cannot see the brand.

[PCBONEZ]

Re: Dell Dimension 4700 with a blown cap

Shield logo = Chemicon.
That is a Chemicon KZJ series.
Chemicon KZJ [and KZG] frequently have problems. [Bad series.]

Specs wise KZJ should be replaced with Nichicon HN or better.
.

[smalltownguy]

Re: Dell Dimension 4700 with a blown cap

Sounds good, thanks. I'll throw the ESR meter on the rest of the caps on the board before I order, just to be safe.

Will update when I have more info...

[Draino]

Re: Dell Dimension 4700 with a blown cap

I am having a problem with the exact same cap in the picture from this post. The PC no longer boots and has an amber led flashing at the front.

The last time this PC ran was after sitting for some time. I left the room after firing it up and when I came back there was a burning smell.

I replaced the psu but that didn't work and now noticed the bad cap. Is it likely the motherboard is fried because of this bad capacitor?

Any help is much appreciated. Thanks,

[c_hegge]

Re: Dell Dimension 4700 with a blown cap

I'd say your motherboard is toast (pun intended).

Capacitor electrolyte does have a smell, but it isn't like burned electronics.

[momaka]

Re: Dell Dimension 4700 with a blown cap

I replaced the psu but that didn't work and now noticed the bad cap. Is it likely the motherboard is fried because of this bad capacitor?

Not very likely. Replace the bad capacitor as well as any other failure-prone capacitors, like Chemicon KZG and KZJ as well as Nichicon HM and HN with date codes from H01xx to H04xx (where "xx" is a number you can ignore).