What I would do is
disable the servo (red swtich on th amplifier PCB on top of the PSU), put
a folded imwipe between the heads and disable interlocks so the drive wil
lrun without a disk instaleld. Then move the carriage frowards by hand
wit hthe thing effectively spun up (the Kimwipe wil lavoid damaging the
heads) and look at the signals i nthe positioner servo circuit with a
'scope. Start wit hthe outputs of the transducer, see if all signals are
present and change as you move the carriage.
I do it the same way - but with a spinning disk in the drive. It comes
out the same...
Sure. and then you drop the test probe in the wrong palce, and it hits
the disk, and...
I prefer to only hav the heads flying when i need them.
FWWI, the HP7900 manual (a drive similar ot the RK05, but with one fixed
and one removeable disk) suggests running it without a cartridge and with
a kimwipe between the heds when doign some of the tests. The heads fly on
the lower disk, the upper heads are jsut on the Kimwipe. When I start
restoring mine, I suspect I will do it with none of the heads flying to
start with.
-tony