Help diagnosing 800XL issues

[Sardonyx]

6 minutes ago, kheller2 said:

Tap the comp line feeding the RF modulator OR can you test your monitor/cable with another non UAV XL?   Obviously there was a reason this XL was listed as for parts.

 

I don't have another non-UAV XL to test with currently, but working on that.

 

That's true - it could have had parts removed or who knows what someone did to it.  Since the RF can output color means the color circuitry is present/working.  It boots to BASIC, is able to load over SIO, run the self tests, etc., so I assume most of it is present/working.  There's likely a memory problem as it fails that self test and tends to crash after running for a bit.

 

I may have to go over it in detail to see if any components have been removed or any alterations have been made.  I haven't seen what's under the RF shield so anything could be (or not be) under there. 

[Sardonyx]

I've now been able to test the video cable on another stock 800XL. The cable is displaying color over composite, so the cable seems to be working fine and can probably be ruled out.

 

I guess the next step is to open up the parts 800XL and see what it looks like under the RF shield. 

 

In the meantime, since it failed the memory test - what's the best source for replacement RAM?  Are these or compatible chip still sold?

Edited August 6, 2022 by Sardonyx