Help bring a heavy sixer back from the dead

[nitrosport]

I picked up a broken sears heavy sixer the other day. When i first got it, it was completely dead. I check the voltage on the power supply and it was fine. I cleaned the power switch and changed the voltage regulator and now it's showing signs of life.

 

Now when I turn it on, the static on the screen changes so it's finally getting power but thats about as far as I got. I can't get it to do anything else. What else should I try?

[robertski]

99 percent of the time, if no random splotched graphics show up, and blank screen, It could be the

Quarts counter is not running at all.. Test For a Signal on an Oscope for the Timing pulse.

 

The other main reason could be that the Reset signal does not KICK in on power-up.

 

This is usually a failed 4.7uF cap that allows the TIA and RIOT to boot before the 6702.. and also

is testable with an Oscope.

 

Or you could just swap out the main CPU and the RIOT, the big chip, being not the TIA.. and see

if that works..

 

Hope that helped.