Korg Poly800/EX800 Users group photo

Yahoo Groups archive

Korg Poly800/EX800 Users

Index last updated: 2026-04-13 23:51 UTC

Message

Poly800 Mk-1 Battery Mod - have I damaged something? Error 1.85001

2015-03-18 by imadethebbc@...


Hi,
I bought a Poly800 last week which worked: I was able to load the factory presets via a .wav file and most of the keys worked. I repaired the keys by cleaning the contacts.

While I had the synth open I decided to apply a battery modification which I found at this location http://analog.no/cms/index.php?option=com_content&view=article&id=50&Itemid=49

I confirmed all of the connections and tested them using my multimeter.
This mod is not the same as the one I've now discovered in the file section.
I removed C87, C88, D23 and D15. I bridged the trace at D15 and cut the trace close to C106
I have not touched R1 or D1

This is a Mk-1 Poly800 which didn't come with a memory backup battery. There are two 'pads' where the battery holder can be soldered.

When I powered up the synth it started ok and I made a simple patch to test that all the keys worked.

I then tried loading the factory presets from a .wav file played back from my phone.

The tape load failed and when I re-started the synth I got the error message 1.8 50 01 on the display (see attached image.

I'm puzzled as to whether something corrupted when I tried loading the factory presets or have I fried something while soldering?

I put all of the removed components back into the synth and re-bridged the cut trace.

The synth is still showing the same error message.


Any suggestions on what I might try next? I'd like to try resurrect the synth and fix whatever I've done.

thanks,

Peter

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.