Tape imaging

shadoooo shadoooo at gmail.com
Thu Aug 11 14:48:21 CDT 2016

Hello Andreas,
nice to see you here from time to time.
I too have two TSZ07, but both had problems with the PSU after some time 
of good working condition.
The problem was always related, as indirect cause, to bad electrolytic 
capacitors, however the effect was always bad.

The first one in the end became somehow over-stressed and had a 
transistor burned to short circuit;
replaced the transistor, and all the capacitors, it was ok.
After the repair operation, one of the motors lost the magnet inside, so 
I had to dismount it, open it carefully,
put the magnet in place with wood parts to keep it in the right 
position, reglue the magnet with acrylic glue, remount.

The second one began suddenly to oscillate badly, so on the 5V output 
there were peaks from 0V to 15-20V...
It remained in the bad state for just 3-5 seconds, then I turned on 220V.
Too bad, a microprocessor on the control board was fried. As I didn't 
find any schematic at the time (and not one so far),
it took me a life with the bare oscilloscope to understand which 
component was defective, ordered it form the US,
desoldered with hot air, resoldered, et voila, it became to life again...
Worked, but I paid more for the repair / components than what I paid for 
the drive...

I know also Holm has such a drive, again problems with the PSU... 

So be warned: replace all the relevant capacitors before operate the 
drive, to avoid problems.
If you want and have some patience, I could take some pictures to show 
you what parts are delicate and what not.
The PSU inside has two boards, one is high-voltage stage, the other has 
the main transformer and the low-voltage stage.
It produces IIRC -12V, +5V (standby), +5V (high current), +12V, +37V.
To test the PSU alone, you need to connect a resistor between two pins 
of a connector (I should double-check in case
you want to know), otherwise it will not power-up, only standby voltage 
will be present, but it's not supplied by the switching high-power circuit.
I recommend a test of one hour or more with load resistors (or lamps) 
and voltage monitoring to test the effective operation.

Let me know if you need some help.

(out of band data): do you have some information about trips to Munchen 
or somewhere in Bayern or Osterreich?
Didn't heard of you anymore lately... We still have the drive swap to 
organize! Please let me know.


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