Rhodes Chroma Polaris

Maybe see if the EPROMs read correctly?   Old EPROMs can sometimes lose bits here and there.
You can erase and reprogram with the same data and they will be fine.   Or you could try replacing the 
SRAM chip(s).   Another idea would be to just pry up a little and push back down a bunch of logic chips.
Since they are socketed, it's an easy thing to do, and can sometimes restore a bad connection by wiping
the contacts a little.   I guess even more drastic would be removing and reinstalling the CPU.   I did help
a friend fix a Polaris that had a bad CPU.  Luckily he had a "parts" board, so we just installed the CPU 
from that one, as an experiment, and that fixed it.   Maybe try the chip pry up then re-seat first, since it's free.
If you have an EPROM programmer, try to read the EPROMs and match them with images on the web.

Maybe Paul D will chime in with some better ideas...  He's the Polaris expert.

Bob
 
--------------------------------------------
On Mon, 8/8/16, lou@... [chromapolaris] <chromapolaris@yahoogroups.com> wrote:

 Subject: [chromapolaris] Trouble with my Chroma Polaris
 To: chromapolaris@yahoogroups.com
 Date: Monday, August 8, 2016, 10:09 PM