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#1 2017-09-28 09:51:08

korax
Member
Registered: 2017-09-28
Posts: 2

Strange checkerboard problem

Hi,

I got a Macintosh Classic. It was running 5 days a week last week for 8 hours each day and I spent the entire night yesterday installing all kinds of software on it. Everything was fine. I turned it on for a short while this morning, also fine. Then I disconnected it from all wires (power and keyboard) and turned it display down to just take a look at something.

When I turned it display down, I think I heard something like a "click" or "pop" sound, but nothing too loud. Then, after a minute or two, I powered the Classic on again and I was welcomed by the well-known checkerboard screen. Needless to say I was unhappy to see that.

BUT, when I powered the Classic on again after an hour or two, checkerboard was gone and everything was working. Curious to see what would happen, I powered it off and on again and the checkerboard was back.

What could be the cause of this? If it would be a bad capacitor, I think I would see the checkerboard every time, right? I also know I might just reseat the RAMs, but again, the problem is sometimes there and sometimes not... If possible, I would like to avoid replacing the capacitors because I'm not exactly the most skilled person to do that.

Does anybody have any idea what could be causing this?

EDIT: I tried it again and it seems the checkerboard problem really appears only when the mac is "warmed up". When I leave it off for like an hour or so, everything seems fine. I'm even more puzzled now.

Last edited by korax (2017-09-28 11:12:45)

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#2 2017-09-28 17:51:30

mcdermd
Member
From: Corvallis, OR
Registered: 2014-05-12
Posts: 972
Website

Re: Strange checkerboard problem

Cold solder joints?


Daily Drivers: 27" iMac 2.8 GHz Quad-Core i7 (Late 2009), 21.5" iMac 2.7GHz Quad-Core i5 (Late 2013), 11" Macbook Air 1.6 GHz i5 (Mid-2011)
See the restored heroes here.

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#3 2017-10-02 04:56:36

macdrone
Member
From: Rainier, Or
Registered: 2014-05-25
Posts: 237

Re: Strange checkerboard problem

capacitors can be intermittent on the logic board, also check to make sure that battery is removed.

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#4 2017-11-11 14:06:22

French
Member
Registered: 2017-06-17
Posts: 7

Re: Strange checkerboard problem

Voltages problem ? Classic and Classic II are prone to Analog Board failure.

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