|Re: 9830 tape drive question|
Message #2 Posted by Tony Duell on 18 Aug 2011, 4:37 a.m.,
in response to message #1 by David Ramsey
No, tht sound is not normal, and may be part of the problem.
Unlike audio cassette recorders, the HP9830 tape drive doesn't use a capstan and pinch roller, it just drives the spools. The tape speed is not constant therefore, but that doesn't matter as the data encoding is essentially self-clocking.
Anyway, there are 2 motors inside the drive on a rocking beam, which is moved by a pair of solenoids, one each side. Each motor spindle can be forced against the rubber tyre of the drive spindle. My first guess is that these tyres, which are simple O-rings, have decayed.
I would take out the tape drive, open in up and look at it.
Start by removing the top cover and the keyboard, then undo the fixing screws and lift the tape drive up and out, it's plugged into an edge connector on the backplane. Take out the screws on each side and ease off the mounting bracket. This carries the connector PCB, and the various parts of the tape drive are connected to this by 'plugs' which are actually little PCBs fitted with pins. Carefully unplug all 4 of these.
There's a metal bracket across the back of the motor assembly. It's held on by 5 screws (2 each side, and one in the centre). Take this off, and slide the motor assembly out too. You can now see the drive wheels and the tyres. There's a sliding brake plate which is sprung against the tyres when the drive is stopped, and this might have made notches in said tyres.
Normally you don't have to remove the drive spindles themselves, but if you want to, take off the front cover next (1 long through-bolt, slide out the window before it falls out, and unscrew the ground wire). Then take off the leaf spring from the back of the drive spindle (1 screw), the circlip on the front side, and the plastic washer. The spindle will slide out rearwards.
My notes suggest a size BS219 O-ring is the right part to use.
Feel free to contact me privately for more information if you need it (and for that matter about any other aspect of the 9830 and 9866).