Insights from full recap and restore of Trayloader G3 iMac

[mattsoft]

Thanks for the write-up! Recapping a bondi blue (rev a) tray loader now, and wow, there are a lot of screws and caps and boards!

 

[alectrona6400]

Great work, 68krazy! Reminds me, I should probably work on a list of caps and a servicing guide for the eMac's analog board. That's something Apple did not intend for the user to service... If you try finding a new CRT, let alone a new analog board, Apple would just give you a whole new top half that goes to the front bezel.

 

[mitchW]

Any info on original caps? Were they still in spec?
I don't think they leak
I know they are pushing 25 year mark, but I have some apple stuff pushing 40 year mark and still going strong with original caps (except RIFAs).

 

[joshc]

Any info on original caps? Were they still in spec?
I don't think they leak

Caps don't have to leak to be bad, but perhaps that's what you're getting at.
iMac G3s are known to have issues, especially on the down converter board, so bad caps in these wouldn't surprise me. And they were very much budget/consumer machines - and also subject to tons of heat because cooling in them is almost non existent, so again bad caps wouldn't surprise me.

 

[mikes-macs]

Anyone want an iMac? I have a rev D 333 MHz for parts, needs work. If you want it it's yours for the cost of shipping or free for local pickup.

 

[coffnix]

yo! I’m having a strange issue with my 1998 iMac G3. It works without any problems initially, but when it’s left on for a long time, a weird bug occurs that’s difficult to pinpoint. After being on for an extended period, my iMac G3 simply goes into a black screen mode if there’s any change in video resolution. Additionally, when I turn it off and try to turn it back on, the power LED stays green, never turning off, and the machine doesn’t power back on. The same happens during a reboot; instead of the LED turning yellow and then green, it doesn’t return from the reboot. Even with the startup chime playing, the screen remains black. The only solution is to unplug it and plug it back in. After being unplugged for a while, it returns to normal, but the bug reappears if it’s left on for several hours, typically two or more. I’m not sure if this is an issue with the mainboard, power supply, or analog board. I’ve already recapped 100% of the capacitors, and while the bug used to be permanent, it’s now intermittent. At first, I thought the recap had solved the problem since I only used the iMac for a short time, but when I use it for longer periods, the bug always comes back. It only stabilizes if it’s unplugged for at least 10 hours. Any attempt to turn it back on after the bug appears is futile. Do you recommend checking any specific chip or shutdown signal? Thanks for the help. Oh, I forgot to mention, only the electrolytic capacitors were replaced during the recap.

This is my imac G3: https://area31.net.br/wiki/Restoring_a_1998_iMac_G3_rev_A

 

[MacUp72]

wow, great work..yeah, caps are quite expensive..
LCD swap is also an idea