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Introduction
I purchased this Commodore 64 at a local meetup. The case was in really great condition but ended up cracking and breaking in the back. The board is a 326298 Revision A board (1982) with a 5-pin video connector. It is in really clean condition and booted to BASIC. However, the keyboard was not responsive and there was no blinking cursor at the BASIC prompt.
Case Study
This one ended up being a really easy fix that took a lot of time to get there. I started by probing the CIA as a logical place to start. This did not yield anything and replacing the CIA did not fix the problem. I was having a difficult time finding anything on the scope and decided to reseat all the chips with contact cleaner (I usually buy WD-40 contact cleaner from Amazon or a local hardware store). Reseating the MOS 901227 kernel ROM (U4) fixed the computer.
Comments
I try to reseat chips with contact cleaner before I do any serious repair work. Oxidation is real and can bring a computer down. This computer also did not have a working SID. I replaced it with a SIDKick Pico I purchased from eBay. I also did a video mod that required adding a resistor (R10) to brighten up the video that is needed on some of these early boards. In addition, I added heatsinks to the ceramic Revision 56A VIC-II video chip. Will need to find a new case for this board. Maybe another from Retro Fusion?
