commodore 64-sx not starting

[monoxrom]

Hello!
I'm have two commodore 64-sx non working computers
Both show only white screen when i'm turning on computer.
I changed the board from one to another, but nothing happen another. Only white screen i see.

I would ask maybe this is sort of known problem of commodore 64-sx computers?
Because i don't know what to do next. Maybe replace capacitors on kinescope electronic block?

 

[sjgray]

The standard reply seems to be... look on Ray Carlsen's pages here:

http://personalpages.tds.net/~rcarlsen/cbm.html

The SX's CPU and IO boards basically make up a C64 computer so many troubleshooting tip apply (just not chip locations).

It might also help to figure out what might be working...

- connect the external video up to another monitor
- plug in a game cartridge to see if there is audio. this might also tell you if there are rom problems
- put in a disk and blindly type LOAD"$",8 to see if the drive light comes on.
- Check the video adjustment dial behind the little door on the front

Steve

 

[monoxrom]

I was replace RAM today
nothing happened, display white like before

 

[dabone]

Did you try an external monitor?

Later,
dabone

 

[monoxrom]

Did you try an external monitor?

If video port is 8 din port near "serial" Then i tried. Nothing i see on the screen (

Oh wait! Signal present but screen fully black

 

[dabone]

See here.


http://personalpages.tds.net/~rcarlsen/cbm/sx64.txt


later,
dabone

 

[monoxrom]

I think i need 906114-01 chip

Can i get this chip from Commodore 64C computer? Or only in the true commodore 64 (not 64C) this chip present?

 

[geoffm3]

Sounds like maybe the PLA chip.

 

[monoxrom]

Yes i need PLA chip..
I want to bay commodore 64 computer and get 906114-01 chip from board

 

[monoxrom]

Yes, that was a PLA 906114-01 chip. I bay new, insert to my SX-64 and computer started working

 

[geoffm3]

Good to hear you got it working! The SX-64 is such a cool computer... we need to keep as many working as possible.