A friend gave me a Superboard II and I just started to troubleshoot it but could use some help from someone familiar with this board. Anyone out there?

So far I've confirmed the following:

* 6502 is good (tested on Asteroids arcade board)
* 2114 RAM good
* Character generator chip good

Problem is on power up I get the expected screen full of random characters from the character gen but the cpu and bus has no activity. Then can bang the break key like a monkey for several minutes and if I'm lucky the bus gets fired up and has activity but the screen does not change to a command prompt like it should.

I have videos I can post and more info if there's anyone interested and can help me try to fix this.

Not much info out there that I can find but I do have the manuals and schematics but hard to figure out what's responsible for what.

Some photos attached.

Here's a vid of the data bus being active (after several minutes hitting the break key and getting lucky it comes to live sort of...)

With all roms installed the screen never changes like it should from the random characters to the main command line prompt to allow you to enter BASIC.


With the BASIC roms removed. When the roms are removed the random characters on the screen go away and we just have noise.