Commodore 64 ‘breadbin’ repair log #1

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Aug 032011
 

Brought 5 broken C64’s back from the RCM to try and ressurect.
This one just booted to a black screen.

On my initial checks I found that the 6510 CPU did not have a clock. The clock for this is outputted from pin 17 on the VIC chip. Although this was getting a clock input, it was dead on the output and was getting very hot. I replaced this with a known good one and fired it up again. Still got a black screen but clocks were now present.

A black screen is commonly associated with a dodgy PLA. I removed the PLA and replaced it with a known good one and the C64 now loaded up.
Next problem, there was no cursor and the keyboard would not type anything. These are handled by IC U1 which is a CIA. Again, I removed this chip and fitted a known good one.

The Commodore now fires up and works fine.
One down, 4 more to go (and a VIC20 but dont have a PSU for it)

Commodore 64c repair log

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May 282011
 

The data cassette player would not power up and there was no sound outputted.
There is a big 1.5A fuse inside labelled F1. This supplies the +9v to pin 28 of the SID chip and is also used in powering the cassette unit.
Replacing this fuse brought everything back to life.

The C64c boots up fine without this fuse. I have been using an SD2IEC adapter to load games and didn’t realise at the time that the cassette unit was not working either.

Amiga Apollo 1230 expansion card repair log

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May 272011
 

My good mate Andy over at RCM gave me his 1230 MK2 expansion card to have a look at last time I was there. The problem was the PLCC socket on the FPU was cracked at one corner.


I did manage to confirm this was the problem by holding the socket together so I ordered some socket from China and removed the old socket
The old one came off easy enough with a hot air gun.

The sockets came and I set about fitting it. I decided to use solder paste as it makes the job quite a bit easier when soldering surface mount things with many pins.
5 or so minutes later the new socket was on and after a quick check under the magnifying glass it was time for a test run.

Workbench reported the extra RAM and my 1200 was now a flying machine so im happy its working. Tried Scorched Tanks to make sure, its the only game that was on the compact flash drive!

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