Well, you seem to be making significant progress. And nothing to do with any of my suggestions. The CPU just didn't have a clock! I should have included that.
Let us know how it goes.
/Mike
From: "kogz23@... [korgpolyex]" <korgpolyex@yahoogroups.com>
To: korgpolyex@yahoogroups.com
Sent: Wednesday, July 8, 2015 12:38 AM
Subject: Re: [korgpolyex] Poly 800 Mk1 display not working
To: korgpolyex@yahoogroups.com
Sent: Wednesday, July 8, 2015 12:38 AM
Subject: Re: [korgpolyex] Poly 800 Mk1 display not working
Thanks for the in depth reply! A lot of what you said is unfortunately above my head. The testing you describe, is that possible with a DVM? Mine does have a logic reader and frequency counter. I just don't know what I would be looking for when checking the different bus signals you list.
Anyway, I found the problem. IC23 pin 11, clk, was not connected to pin 30 of the CPU. Made the connection and the display came to life. Now to test the machine.
Thanks again,
Al
Anyway, I found the problem. IC23 pin 11, clk, was not connected to pin 30 of the CPU. Made the connection and the display came to life. Now to test the machine.
Thanks again,
Al