View Full Version : A strange problem with Commodore 64

April 15th, 2008, 08:25 AM
My friend gave me his old Commodore 64 which he hasn't used for years. I plugged it into my TV and switched it on, but it only showed an empty, blue console screen without any text on it. So, I waited for a while for the Commodore BASIC V2 program to start, but it didn't start. Even after a half an hour it still showed the empty blue screen. After a few more tries I plugged Commodore's own cassette-recorder into it, and something strange happened: the Commodore BASIC V2 finally started! But after I shut the computer, next time it again didn't show anything else than the blue starting screen, even if I used the cassette-recorder in it. Can anybody tell what's wrong with my Commodore 64 or am I doing something wrong?

NOTE: Sry if there's typos or any grammatical errors in my text, my native language isn't English :sleepy:

Bungo Pony
April 15th, 2008, 09:25 AM
I've had problems getting the display when the power supply was acting up. And judging from the amount of C-64 power supplies in my collection, it seems to be a fairly common problem.

April 15th, 2008, 10:39 AM
Does the blue screen have a different colour border around it or not?

April 15th, 2008, 12:01 PM
Does the blue screen have a different colour border around it or not?
Yes, it has. The screen is like it should be, a little bit darker blue box inside the whole screen filling lighter blue box... For some reason it does not load the Commodore BASIC V2, the booting just jams into empty, blue screen like in the description above... :(

April 15th, 2008, 02:56 PM
Do you have any game cartridge or other things to test? As per Ray Carlsen, it is most likely to be the Basic ROM chip that has gone bad. Many games bypass the Basic, so if a game would work it is a way to diagnose.


April 15th, 2008, 07:03 PM
From my notes back then, the three most likely causes were a bad 4164 RAM chip, a bad PIA and, in one case, a bad character generator IC.

Bad RAM was far and away the most common cause and, in one instance, it was one of the 2114 video RAMs. The text was there, but it was the same colour as the background.

Terry Yager
April 16th, 2008, 11:06 AM
Notes? What a novel concept...wish I'd been taking 'em all these years...