Anyone got a schematic on a Lexicon MRC Midi controller?
I have got two dead ones i have been trying to get going for
customers for awhile. Kind of hard with no prints. Essentially
a one board computer with Z80, 4 rom, static ram, uart,analog
input chip, and display controller.

Unit #1 will go though self test until it get to the Duart test
and them the display goes to gibberish and unit locks up.
Subbed the CPU, RAM and Duart from another working unit and all
the symptoms stayed the same.

Unit #2 comes up with display solid, no activity. Swapped
CPU,RAM,DUART and still the same. Now, this unit has the
CPU reset line staying low. I think this is related to the
problem but need to find the circuit that controls the CPU
reset on power up. I am hunting down some generic Z80 circuits
for a guide.

Both have the EL panels out, but that's a moot point with no
brain activity........

Bob

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----