Commodore 64 won't boot up correctly

[The Mr. Video]

Hi, yesterday I turned on my c64, only to have it display a black screen with a dim power LED, which then turns to a white screen. It does correctly boot up, but that rarely happens. Any help would be nice.

[carlsson]

Is that a dark grey/brown breadbox style model? If so, my bet is that you've got a faulty PLA chip. It is probably the most common fault on early C64 models (*). Replacements vary, most common these days are chips like SuperPLA and realPLA (you might find more vendors if you research those terms + C64 to narrow search results).

 

Depending on your level of DIY skills and available tools, here is a VHDL implementation: http://www.frank-buss.de/c64/pla/

 

Previously, people have programmed very fast EPROMs to act as PLA chips. As always, there is a lot of heated discussions whether that is good practise or might cause more damage. Here is a thread from the Lemon64 forum that has run for three years:

http://www.lemon64.com/forum/viewtopic.php?p=537478

 

(*) Actually including some of the first C64C models too, those with the older motherboard, 6581 SID and graphical symbols on the front of keycaps instead of the top of them.

Edited December 26, 2015 by carlsson

[7800fan]

Also if you are using original power supply, unplug it ASAP. Black box PSU is prone to failing and dumping incorrect voltage to the system, killing it. There are safety device that can be used or a better made PSU.

 

http://personalpages.tds.net/~rcarlsen/cbm.html good place to start on this issue and maybe he can sell you something for the power supply.

[motrucker]

This problem is hard to pin point, without a multimeter, but the two suggestion so far are right on the money. Are you using an original "black brick" PSU? My money would be on the PSU, if this is an occasional problem.

 

 

[The Mr. Video]

My new third-party PSU got delivered today, I tested it out and it works! Now I can finally play the games I bought for it. Thanks for the help!

[+save2600]

Out of curiosity, did you purchase one from the link above or was it another 3rd party PS available somewhere else?

[The Mr. Video]

Out of curiosity, did you purchase one from the link above or was it another 3rd party PS available somewhere else?

It was a third party PS from somewhere else.