Description
image 1:
Relatively normal startup screen, but frozen with a rapidly flashing cursor and ‘LOAD’ command run automatically. No response to keyboard commands. A cartridge game loaded up properly but joystick and keyboard did not work. Picture re-created with VICE C64 Emulator.
Image(s) by Ozsoft @ lemon64.com
images 2,3,4:
Caused various abnormal startup screens, including a simple black screen on a couple of boots. The most common outcome was an empty blue screen with borders (first picture). After about 10 seconds of waiting, most of the normal startup text appeared along with some garbage characters, and in some cases automatically typed load/run commands (second picture). Sometimes the characters kept switching between upper and lower case. On one boot, screen was filled with white garbage characters (third picture). The computer seemed unresponsive on every boot.
Though in this case the problems were simply caused by a bad connection between the CIA1 chip and its socket, similar symptoms can likely be caused by a failing CIA chip.
General
Startup screen normal, but no cursor. No keyboard or control port access but cartridge works. Partial failure: some keys or joystick positions don’t work, one character appears ahead of startup cursor or random characters appear at startup. Blank screen if chip is shorted (remove to check) and chip may get hot to the touch.
Cause
– Bad 906108-02 (6526) CIA
– Bad socket contact on U1 (CIA) – bottom pin(s)
