1 Sep
2011
1 Sep
'11
4:28 a.m.
I used my digital multimeter to check the pins you
mention, there is
continuity
between pins 26, 28, 30 and 32 on each of J1 to J4. I
also checked that
pin 4
on J9 is connected to pin 12 on J12, this is the RD 0
RDY H signal, so the
drive
should be seen as ready by the RQDX3. I have also
checked that J5 pin 1 is
connected to J12 pin 14 which is the select ack (DRV SEL 0 ACK (L) ), so
any
selection confirmation should be coming back to the
RQDX3.
I suspect I need a way to monitor the signals actually passing across the
wires, I
have a multimeter and an oscilloscope, but I am not
sure of the
practicalities
of how to get access to the signals, I suppose I need
some kind of
"breakout"
ribbon cable, but I don't want to ruin the
existing cables. Is there some
standard technique for doing this kind of work? For now I think I will
just
solder some diagnostic wires directly to the M9058.
Hmmm.... I used my multimeter to see if I could see anything happening. I
could see that the controller selects the drive and that the select
acknowledgement is asserted (J12 pin 14), so it seems the disk is responding
to the controller and the controller is seeing the ack. I then used my
oscilloscope to check the INDEX signal to see if, once selected, the drive
told the controller it was seeing the start of the track, I confirmed this
was happening, so the disk is rotating.
So why it thinks the disk is offline is a mystery.
Regards
Rob