Hello fellow Poly800 users!
I have been talking to Mike via email about my poly 800 mkii issue, but I figured I'd post to the group as well to see if there is any input on the matter.
I picked up an "as is" poly800 mkII on ebay a few weeks ago. The synth wouldn't turn on at all. I opened it up and noticed many parts damaged by poor soldering/repair work in the power supply, namely Q1, which had several damaged traces. I repaired the traces, pulled another 774B from a partially working poly800 I had in my garage as well as a couple diodes and replaced those. The poly800 would power on, but the display reads "9.9.9." in the first 3, 7 segment displays to the left. It makes no sound and generates no midi data. I have tested the power supply and the +5 v calibrates fine, but the -5 volt sits at about -4.7v on boot, and then slowly decays over a couple minutes down to -4.6 and so on. Q1 gets extremely hot as well. I noticed pulling the eeprom on the digital delay board does not change the state of the synth, could it be a bad eeprom?
thanks! any help is appreciated!!
n8