blown motherboard caps

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Joined: Jan 20 2005
Posts: 700

I've been using my quadra more in the last 2 weeks than the last 4 years ive owned it. last night it randomly crashed and when i tried to reboot i got the "bad chime" so i checked all my connections, nothing i did made it boot. with my LED flashlight i noticed some shiny stuff around the caps that actually bubbled when the machine was turned on! i then realized this has happened all over the board. so its time to replace the caps and give it a full wash down.

the question is where do you all prefer to get these caps? i need to get some for my PB100 also so i can restore that. a whole bunch of them even between the two machines are the same values, G4 47 @ 16v. there are a few smaller ones on the PB100 as well.

thanks in advance!

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-Justin
(dead) PB100, Q650, PB Wallstreet, beige G3, Imac snow 600, Ibook g4, SE30, (dead) IIsi, TiBook 667VGA, PBg4 1.5, MDD dual 1.25ghz, 1.8ghz g5 tower.
OS7.5 to 10.3.9. I LOVE CLASSIC MACS!

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eeun's picture
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Joined: Dec 19 2003
Posts: 1891
Re: blown motherboard caps

Uniserver and Trag over at 68kmla.org sell sets of caps for a reasonable price.

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"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

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Joined: Jan 20 2005
Posts: 700
Re: blown motherboard caps

another question is whats the best way to clean these boards? i was going to use rubbing alcohol and a tooth brush...

__________________

-Justin
(dead) PB100, Q650, PB Wallstreet, beige G3, Imac snow 600, Ibook g4, SE30, (dead) IIsi, TiBook 667VGA, PBg4 1.5, MDD dual 1.25ghz, 1.8ghz g5 tower.
OS7.5 to 10.3.9. I LOVE CLASSIC MACS!

eeun's picture
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Joined: Dec 19 2003
Posts: 1891
Re: blown motherboard caps

I just bathe the boards in a washing tub with a little dish soap and scrub with a 1.5" soft paintbrush. Rinse, then blow off the remaining water with compressed air. I leave the board for a day just to be sure.
On the Color Classic I just got that had leaky caps, this got it running again. I did have to hit a couple spots around the worse leakage with 99% isopropyl alcohol and a soft toothbrush, but most of the work was done with water. The board now looks like new.

If you have hard water (ie - water with a high mineral content) I'd recommend buying a jug of distilled water for at least the rinsing part of the process.

I've seen quite a few posts recommending running a board through the wash and rinse (but not dry) cycle on a dishwasher. Not having one, I can't comment other than so say others seem to have good success.

I should replace the caps on the CC at some point, but I'm reluctant to start deoldering on what is currently a working board.

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"Give a man a fire, he's warm for a day. Set a man on fire and he's warm for the rest of his life."
(Terry Pratchett)

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Joined: Jan 20 2005
Posts: 700
Re: blown motherboard caps

totally understandable, why take it apart if it works? thanks for the info!

__________________

-Justin
(dead) PB100, Q650, PB Wallstreet, beige G3, Imac snow 600, Ibook g4, SE30, (dead) IIsi, TiBook 667VGA, PBg4 1.5, MDD dual 1.25ghz, 1.8ghz g5 tower.
OS7.5 to 10.3.9. I LOVE CLASSIC MACS!

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Joined: May 27 2013
Posts: 794
Re: blown motherboard caps

I get my capacitors from Digi-Key: http://www.digikey.com/ You can search their website and filter all of the characteristics of capacitors you want. Brand name, voltage, type, capacitance, temperature... I usually choose Nichicon.

Here's a good read: http://www.badcaps.net/pages.php?vid=4