| previous by date | index | next by date |
| topic list | next in topic |
Hey guys,
I picked up an old Poly800 with a couple problems. The tuning slider didn't work, the pitch bend on the joystick didn't work, and the unit won't accept AC power. It does run off batteries just fine.
When I cracked the case I found that someone had done a really poor job of installing a battery mod. They soldered in a 1/2 AA Lithium Ion battery but managed to get about 3/4 inch of excess solder from the negative pad of the battery across 5-6 of the traces. They also removed the component at C88. I desoldered the battery and wicked up the excess solder and found that one of the traces was broken (the one immediately below the negative pad in the attached picture). I repaired the trace and got continuity. The tuning slider and pitch bend then started working!
However, I have 2 issues now that I can't seem to sort out myself.
1. Whenever I turn the power off to the synth for longer than about 10 minutes, it loses all its programming. This happens WITH the C-cells still in it. I believe this has something to do with component C88 being removed but I'm not sure. I have ordered the Hawk800 + Atomahawk mods. My understanding is that the mods negate the need for any sort of battery powered memory so do I even need to fix this issue? If so can someone help me ID that component? I'm having a hard time reading the schematic....
2. AC power won't work. Component D2 has been reduced to ash near the AC adapter. There also appears to be some more ham-fisted soldering and I can't tell if there is more wrong than just the burnt component. Can you guys take a peek at the attached picture and let me know what you think? Do I just need to replace component D2? I picked up some 9.1v zener diodes but can someone confirm that this is the proper component?
Thank you,
-J
