12 Jan
2013
12 Jan
'13
4:34 a.m.
On 1/11/2013 4:08 AM, Rik Bos wrote:
cs for the HP9830.
You can download the HP 9830 service manual at the Australian HPmuseum
website.
Most boards used in the 9865 are the same as in the HP 9830, I know for
sure.
The only boards that differ are the interface logics and the tape drive
board with the head amplifiers on it.
Cool. I wasn't aware that the 9830 had a similar cassette drive in it.
I've now got the service manual and it looks like it should make
tracking down the problem fairly straightforward. I hope. :).
I suppose you looked at the pictures I made from one
of mine on flickr,
http://www.flickr.com/photos/hp-fix/sets/72157630819381098/
After you checked the motor drive board, look at the IO card (A61) because
that board contains some 7403 's U1 and U3 which have a tendency to fail.
If this board fails you get errors which seems to point to other components,
so it should be check before you look at other boards.
The manual is very handy when looking for problems, you can find there a
description of all the signals with fault indications.
But also check the interface card, that also can be a pain in the ass (you
should ask Tony friendly if I may send you the diagram of the interface).
Thanks. At the moment, it looks like the interface is working properly
-- the forward motor spins up OK, it just doesn't get engaged by the
solenoid properly. (And other functions under control from the 9810
work OK.) Hopefully it's just the circuit for the solenoid that's at fault.
You also should look at the LDR from the tape sensor next to the head, they
have a tendency to go to a high resistance > 1k.
The result of that is no fast forward winding because the sensor never
'detects' the darkening of the tape.
That seems to be working OK. It rewinds/forwards slowly until it passes
the lead-in and then it speeds up.
Thanks!
Josh
I think the board you want to be looking at (and
I am doing this from
memory) is
the 09865-66564. There's a little logic and a
couple of transistors to
drive the
solenoids.
I assume the solenoid isn't burnt out ...
Not likely..
-Rik