Cossor 1045K Oscilloscope
 

I'm trying to repair a Cossor 1045K Oscilloscope and would be grateful
if anyone could point me in the direction of the service / operator
manual. I can find a copy of the circuit diagram from www.mauritron.com,
but ideally I would like to get a copy of the full manual.

The CRT appears to be working fine as the X and Y position adjustments
work. When I connect the Y input to the built in 1V pk-pk AC test
signal the scope displays a vertical line, but the test signal itself
appears to be ok. Changing the timebase makes no difference to the
display and the output from TB OUTPUT is a constant 187V DC. The end
of a wire that is connected to the timebase switch has come loose, but
it is not clear to where the other end should be connected. If anyone
has a working example I would appreciate if they could tell me to
where this wire should be connected, it is the short black wire from
the bottom of the rotary timebase switch (the pin that also has a wire
to the 2 uF capacitor that is mounted on the switch and another red
wire connected).

Thanks,

Mark