OBERHEIM SYNTH

As your tech should know, after checking the power supplies,
you would check the oscillator to the CPU, and also the reset signal 
to the CPU.   If those are OK, then try reading the EPROM that holds
the code, to make sure it's still intact.   (At some point you may also 
want to upgrade to the one that's on my site, tauntek.com, but only
after you get it fixed)   If everything is OK so far, then scope the 
address and data lines coming from the processor and look for strange
voltage levels, which would indicate a signal that is shorted to vcc or gnd.
But test the synth first to see if maybe it's working and just the display 
is bad.   That would be a different situation.

The service manual for the Matrix 6 is available, so your tech should
get that if he doesn't have it.  It's a free download.   It least then he will 
have the schematics.

Bob


--------------------------------------------
On Tue, 2/23/16, fknchino@... [oberheim] <oberheim@yahoogroups.com> wrote:

 Subject: [oberheim] Re: Oberheim Matrix 6 Display Issues?
 To: oberheim@yahoogroups.com
 Date: Tuesday, February 23, 2016, 1:59 AM
 
 
 #yiv2231702039 #yiv2231702039 --