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Leaking Capacitors in iMac G5

keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
I just opened up one of our iMac G5's (Rev. A) to install memory yesterday and saw 2 leaking capacitors and 2 bulging capacitors. :eek:

Turns out Apple had some problems with these awhile back and have an extension repair service, but this machine does not fall under that (it's a refurb).

In any case, I have no idea how long they've been bad, or if they are a risk (fire?). The machine seems to run just fine.

Should I be concerned about this? We don't want to replace the logic board for $900. I don't want to try to replace the capacitors, although some people have done it succesfully.

Any input appreciated.
 
Luap

Luap

macrumors 65816
Jul 5, 2004
1,249
743
My rev a G5 iMac had this problem too. I started to get video artifacts, that gradually got worse and worse, then the mac would lock up completely after a short time.
It was only just inside the warranty period when this happened. Still, it was repaired and has been fine for 2 years now. The repair guys did mention it was the caps that had failed, in the same manor as you described. But of course the boards are not serviceable by Apple, even for just simple/cheap components like caps. So the entire mobo was replaced. Bit of a waste, but there you go..
I imagine for someone with competent soldering skills, it would not be too hard or expensive to fix though.

I dont want to put a downer on things for you, but the failing caps will affect the operation of the computer sooner or later..
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
Luap said:
I dont want to put a downer on things for you, but the failing caps will affect the operation of the computer sooner or later..
Click to expand...

That's OK, we're resigned to that... eventually it will just die. I'd like to be able to solve such a cheap-o problem cause I've heard caps are really inexpensive, but I just don't have the time or expertise. I think the whole computer would have to be taken apart which could likely lead to an even earlier death of it.

I guess we'll just run it until it completely chokes, unless someone says it could be hazardous.
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
flipperanubi said:
Caps can be quite easy to replace.

Someone with good soldering skills should be able to change those caps out for you.

Cost of components should be a few bux at most. Cost of letting it go...very, very expensive.
Click to expand...

Any body on these boards have any experience replacing caps? :confused:
 
R

rpp3po

macrumors regular
Aug 16, 2003
171
0
Germany
Cut the damaged capacitor forcefully through the middle (horizontally) with a side cutter. Then try to carefully remove its lower half while preserving the two pins connecting it to the logic board. The longer the pins' length the easier soldering will be. Remember which pin is plus and minus (printed onto the original capacitor). Bend the pins apart a little and cover them with solder (don't let it get hotter than needed). Do the same with the replacement capacitor's legs. No need to cut them as short as the original ones. Just leave 'em as they got shipped. Then solder each leg to each pin remebering which was plus and minus. Now carefully separate both pins with insulating tape. Then wrap tape around both insulated pins together and the capacitor. Finally carefully bend the whole package into place to make it fit into the case again.

Exercise maximum caution that the insulated pins don't touch each other and that the tape doesn't shift while bending the package into place!

Instead of $900 just a few cents and a little bit of spare time. It really isn't that hard.
 
Luap

Luap

macrumors 65816
Jul 5, 2004
1,249
743
keysersoze said:
Any body on these boards have any experience replacing caps? :confused:
Click to expand...

Any chance you can take a pict of the failed caps?
Its something I could probably repair myself, if it happened to my iMac again. But im in the UK, so likely no use to you.
There was a very similar problem with the MK1 Apple airport base stations some years ago. I ended up fixing 2 of those base stations myself. Again, failed caps that were quite visibly knackered.. Bulging and leaking gunge.

But again, anyone with moderate computer experience and good soldering skills could probably have that fixed quite easily and cheaply. I'd really be surprised if the parts alone cost much more than $10

If you have a google around, you'll find quite a bit of info on the problem. Heres one i found just now..
http://www.macnexus.com/index.php?option=content&task=view&id=306&Itemid=2
This also contains a link to http://www.badcaps.net which documents the problems across many manufacturers, not just Apple. It seems they also offer a repair/recapping service.

While im here, I doubt the machine will be in any way dangerous to use.
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
rpp3po said:
Cut the damaged capacitor forcefully through the middle with a side cutter....
Click to expand...

That sounds a lot easier than what I read on badcaps.net. They seem to advocate pulling out the entire old cap rather than reusing the old caps legs. Won't chopping a bulging capacitor in half leak electrolyte? Or does the bulging indicate it's already 'solid?'

I agree if it can be done, it's worth doing, but I'm not expert at this. Maybe I'll find someone who is.
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
Luap said:
Any chance you can take a pict of the failed caps?
Its something I could probably repair myself, if it happened to my iMac again. But im in the UK, so likely no use to you.
There was a very similar problem with the MK1 Apple airport base stations some years ago. I ended up fixing 2 of those base stations myself. Again, failed caps that were quite visibly knackered.. Bulging and leaking gunge.

But again, anyone with moderate computer experience and good soldering skills could probably have that fixed quite easily and cheaply. I'd really be surprised if the parts alone cost much more than $10

If you have a google around, you'll find quite a bit of info on the problem. Heres one i found just now..
http://www.macnexus.com/index.php?option=content&task=view&id=306&Itemid=2
This also contains a link to http://www.badcaps.net which documents the problems across many manufacturers, not just Apple. It seems they also offer a repair/recapping service.

While im here, I doubt the machine will be in any way dangerous to use.
Click to expand...

Thanks for all the info! Unfortunately I don't have a camera, but I bet they look just like how you imagine them to... :)
 
Luap

Luap

macrumors 65816
Jul 5, 2004
1,249
743
keysersoze said:
Thanks for all the info! Unfortunately I don't have a camera, but I bet they look just like how you imagine them to... :)
Click to expand...

In that 1st link is a pict of a board with failed caps. Probably looks much the same as yours does?
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
Luap said:
In that 1st link is a pict of a board with failed caps. Probably looks much the same as yours does?
Click to expand...

Yep! 2 look just like that. 2 others have brown crud all over the tops.

That first article had some great advice "If you suspect bad caps, don't put your face near them while the system is powered up, and don't eat the paper or electrolyte that they blow out!"

LOL
 
R

rpp3po

macrumors regular
Aug 16, 2003
171
0
Germany
keysersoze said:
That sounds a lot easier than what I read on badcaps.net. They seem to advocate pulling out the entire old cap rather than reusing the old caps legs. Won't chopping a bulging capacitor in half leak electrolyte? Or does the bulging indicate it's already 'solid?'
.
Click to expand...

Yes. It's really much easier and safer. Of course it can still contain liquid. I just implied that you clean up any mess the whole procedure would have caused. Wrapping the capacitor into toilet paper while cutting is also a good option.
 
keysersoze

keysersoze

macrumors 68000
Original poster
Jan 6, 2004
1,596
11
NH
rpp3po said:
Yes. It's really much easier and safer. Of course it can still contain liquid. I just implied that you clean up any mess the whole procedure would have caused. Wrapping the capacitor into toilet paper while cutting is also a good option.
Click to expand...

Well that's very good info. I think I will crack the iMac open later and see how much legs those capacitors have to work with.
 
R

rpp3po

macrumors regular
Aug 16, 2003
171
0
Germany
keysersoze said:
Well that's very good info. I think I will crack the iMac open later and see how much legs those capacitors have to work with.
Click to expand...

Usually if it is industrially manufactured, like your Mac, they will be very short. But that's the trick of cutting through the whole package. Usually the legs continue up a few milimeters inside the capacitors before they are connected to the foil and you can take advantage of that.

I would advise not turning on your machine anymore until this is fixed. The broken capacitors can lead to the destruction of other components as transistors. As soon as they fail, the board is practically worthless as there is no way anymore to identify the broken components visually (as easily with capacitors).
 
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