Archive of the former Yahoo!Groups mailing list: Korg Poly800/EX800 Users

I managed to fix the "11 50 01" problem on one of my Poly 800's.

IC 33 was shot on the pin that takes input from key "7".

So every time I powered up the keyboard it would immediately jump into
the display configuration "7- P" or if I enabled the sequencer switch
then it would jump into "11 50 01".

I checked all of the lines from the switches to chips IC 33 and IC 34.
Making certain that there were no shorts and no breaks in the lines.

Also had to check the DTC's that are involved with all of the switches.

I then checked the resistor ladders BR3 and BR9 to make sure all of
the resistors were OK.

I then checked that all data lines were ok between IC33 and the CPU IC24.

After all of that, I was reasonably convinced that it just had to be
IC 33. So I swapped it out for a new one and bingo! She works.

Mike.