Blank blue screen with some erroneous characters and a black line of characters at the bottom of the screen. Dead test produced a dotted display along with some erroneous characters (second picture). Diagnostic cart also had some incorrect characters on screen (third picture). The computer passed the dead test just fine, but the diagnostic cart, which does more in-depth tests, reported a RAM fault. Replacing the RAM chip at U21 resolved the issues.
Contributed by Adrian's Digital Basement
Bad U21 (RAM)
