Anyone has the service manual #20210 for this unit ??
This was made in 1990.
Can u email me the biais adjusment procedure.??
Thanks

Look man, this is not rocket science.

How many channels the amp got, at least two right ? Just match the
channel you fixed to the channel that still works.

Note that if bias is WAAAAAY off you probably have some other bad
components. This needs to be dealt with before putting the unit back in
service, otherwise it will be back.

If you got it fixed right, you match the bias cold then hot, then check
it cold. If it's within 25% cold again then ship it. If not you're not
done.

JURB