Korg Poly800/EX800 Users

That looks like a sequencer step display. Did you accidentally move the sequencer enable switch on the back?
Don B.

From: mailto:korgpolyex@yahoogroups.com 
Sent: Wednesday, March 18, 2015 5:27 AM
To: korgpolyex@yahoogroups.com 
Subject: [korgpolyex] Poly800 Mk-1 Battery Mod - have I damaged something? Error 1.85001 [1 Attachment]

  
[Attachment(s) from imadethebbc@yahoo.com [korgpolyex] included below]
 




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  
        http://analog.no/cms/index.php?option=com_content&view=a... 
      Analog synthesizer Modifications, Poly-800 MK-1 memory backup battery The Poly-800 didn't have any dedicated battery for keeping the patch memory.   
      View on analog.no  Preview by Yahoo  
     


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