Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

previous by date index next by date
previous in topic topic list next in topic

Subject: Re: PolySix only works in test mode?

From: ciolac@pragmatrax.com
Date: 2019-04-23

Hi,

Have you fixed the PCB bugs listed?
https://sites.google.com/site/jedjorgensen/klm367a/images/pcb-bugs-errors
The test mode is used for the D/A adjustment, see the service manual/8 Adjustment Procedure/3 KLM-367 check and adjustment/(2) D/A adjustment.
The schematics show the test switch being checked by the CPU for a low on P16 (pin 31). When P16 senses a low level, the CPU will run the test sequence for D/A adjustment, and display the test values on the program leds. So, it’s not right to run the board in test mode and expect normal operation.
I have not seen the PCB you purchased, but since it works in test mode, although it should not, it’s most likely that the PCB markings for the switch positions could be wrong, On the original board, in normal operation the switch is towards the CPU.

Best,
Alec