iMac G4 recap

[mattsoft]

After seeing some nasty caps on a beige G3 Power Mac, I decided to open up my beautiful iMac G4 and check the caps. A quick visual inspection looked good, but you know what can lurk beneath. I removed a few of the SMDs and sure enough... While there wasn't any liquid on the board, there were beige crusties under the caps. So it's off to DigiKey to order a full set of caps for replacement. Suppose the power supply probably should get a recap too -- but will have to tear this thing down further to get at it. Others recapping their G4 iMacs as well? Just curious. If so, what are ya'll doing about the display? I've never opened one but I'm sure there are SMDs in the display? 

 

[Cory5412]

To the best of my knowledge, the only thing from this era that needs a recap is the eMac 1.25 and possibly some 1.42 models, and the iMac G5 1.6 and 1.8 models. Unfortunately: those all needed recaps in roughly 2005 when they were all still current systems.

Other than that specific instance, which was industry-wide(1) - these are almost certainly too new to need it, and, as we know from the handful of 68k Macs that don't tend to need to be recapped, despite their advanced age, it is possible these will not need it for a very long time.

The thing I'm now curious about is, in the next decade, will yours or stock machines from this family need a re-recap or a first recap first.

(1) Most Pentium 4s that had capacitor failures had them because fraudulent capacitors made with badly stolen formulas was an entire industrial problem at the time, impacting computers, cars, washing machines, stereos, so-on and so-forth, not because the Pentium 4 ran hot, as I have seen in some scenarios. Same with the G5 in the iMacs, it was the capacitors themselves, not the heat of the chip causing the failures.

 

[Daniël]

What do you mean by "beige crusties"? If it's dots of hard material, that's glue used in the manufacturing process to hold components on the board ahead of wave soldering.

 

[mattsoft]

What do you mean by "beige crusties"? If it's dots of hard material, that's glue used in the manufacturing process to hold components on the board ahead of wave soldering.

Not the red/brown glue dots of glue from holding the cap, but beige/light brown crust under the caps around the legs of the caps. It looks like dried electrolytic from inside the cap that has slowly leaked out.

 

[joshc]

At this point, these are 17-19 years old now. I would vote for recapping while you've got the thing open. It sounds like what you are describing is electrolytic leakage, though some photos would be interesting to see.

 

[mcbeav]

This is a few years old, but I recapped my PSU and the logic board of my 20", but there was 1 SMD cap I left, because I couldn't quite tell 100% sure if it was a cap. it looks like a tiny 2mm SMD electrolytic cap. I left it mostly because I missed it when I ordered my caps. I didn't touch the LCD panel yet, but I do want to recap the LCD at some point. I wanted to essentially refurb my system, I replaced all the thermal pads and paste with better quality stuff, cleaned up the board and recapped everything. I didn't notice anything leaking, but it's 20 years old. Preventative maintenance. I've recapped just about all of my collection so I don't have to worry about it.