The processor board only ask to the voice board to run the procedure. The timing tests are done by the voice board CPU and the 8253 Intel chip. So I had no idea about the origin of the problem.
Kris
Le 10 juil. 2012 ¨¤ 12:36, Terje Winther a ¨¦crit :
?
> So you swapped the connectors between the 2 voices boards.
Yes. I had to swap the boards in order to do that, because space is
limited.
> We are agree that it was the connectors at the upper right corner,
> right ?
Yes, correct. The flat cable.
> I ask because I don't understand how the swap displaced the problem
> since there is no tuning specific wires on the connectors. This is a
> classic CPU bus.
Yes it is, but doesn?t the tuning procedures resides on the processor
board? If so, there has to be some communication between the processor
board and the voice cards while doing the tuning.
The M-12 always tells me that the top board fails tuning. If I swap
the boards, it is still the top board that fails tuning. So depending
on the position, the voice board either fails, or is perfectly in
tune. That tells me that there is nothing wrong with the voice boards,
but I could be mistaken in this.
I have taken out and re-positioned many of the ICs on the processor
board (I didn?t move the RAM og ROM ICs, because the auto-test told me
that these were fine), and did notice that some were a bit loose.
Reseating them all didn?t change anything, though, but I haven?t
tested if all the ICs are OK.
Terje Winther
terje.winther@...
