Commodore 64 trouble. Please help!

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thangtamfive
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Commodore 64 trouble. Please help!

Post by thangtamfive »

I bought a C=64 yesterday, and when I turn it on, it works fine for about 20 minutes, but after that it always shuts down. Blank screen, no response. When I switch it off and on, it works for a few seconds and then shuts down again. When I let it rest for a while (a few hours), it works, but again shuts down after 20 minutes. I assume something is overheating?

The only other thing I've noticed is that the background noise -- that soft "whirring" that sounds a bit like a small electric fan or motor -- is a bit loud on this machine. Could that be related?

Any thoughts would be tremendously appreciated. Thanks!!
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LoneWolf33
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Re: Commodore 64 trouble. Please help!

Post by LoneWolf33 »

Hi,

When the machine stops working it may worth to check the +5V supply on the user port edge connector pins,
while the power switch is still on.
(1st and 2nd pin from the left at the top side of the edge connector, 1st is the ground, 2nd is the +5V supply)
If the voltage is below 4.8V that may suggests power supply problem. In this case you can try to borrow a known good PSU
to see does it make any difference. If the problem persists then it's probably mainboard related.

The whirring noise usually indicates power supply filtering problem on the mainboard and/or inside the PSU brick.
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