Have you tried a HARD reset on the keyboard.
In Reply to: QS + going haywire / out of tune posted by John Brinkman on October 27, 1999 at 11:25:32:
: I have a QS + piano that while in the middle of playing from the keyboard OR while playing a
: midi file, goes out of tune. The notes actually sound like somebody is playing with the pitch wheel
: while I am playing. If I restart the keyboard it may or may not be Ok after that. Also, if it is doing
: Ok and I adjust the pitch wheel at all, it will go harwire and every note played after that will
: sound out of tune. Wondering if I need to take it in for repairs or what.....
My QS6.1 was acting strange until I did a HARD reset ( turn the keyboard off ---press and hold 0 and 3 while turning it back on.
This resets everything to the default factory settings. Any modifications that you have made will be lost but the keyboard
should act as it did from the factory. You will have to check your manual for the proper proceedure for resetting your QS8.
hope this helps