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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: bjjones37 on January 07, 2015, 05:58:24 PM
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A few years back I got an A4000 from ebay that work for a few months and then quit working. I have acquired another since. I originally thought I had a bad motherboard, but I have since confirmed that the A3640 is bad. It is a rev 3.0.
I noticed that pin 5 of U200 has been cut off the chip and pad 5 and six shorted together. I have read about the partial 3.1 upgrade where this is done with pins six and seven but I have found no references to pin 5. Is this a factory mod or did someone just screwup the upgrade? Could this have damaged the board?
Should I try to reverse it? There seems to be a tiny bit left of pin 5 on U200 that I might be able to jumper.
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That modification is not correct, the correct modification is documented here (http://amiga.serveftp.net/A4000_HardwareGuide/a3640ref.html).
You can buy new 373 octal latches easily enough if required. But yes, you should reverse this modification and re-do it correctly.