The machine's three rubber drive belts
were broken from old-age but I was able to find a set of belts
that are approximately the correct dimensions.
I removed the chassis and detached the motor lower bearing. I
was then able to thread the two main reel drive belts through
the aperture provided and pass them round the pulleys.
The third belt was fitted to the counter.
There were several minor electrical faults present.
There are three fuses fitted at the rear power selection panel.
The mains fuse was intact. The 1.6A fuse was intact but fitted
in the place of a smaller 100mA fuse. The latter fuse was fitted
in place of the 1.6A fuse and was open circuit.
Fitting correct fuses restored power to the amplifier.
I carried out checks on the audio power output stage and found
the standing current was wrong at 90mA. I made adjustments and
this is now correct at 50mA.
I also tested the power transistors, together with three driver
transistors as these are employed in a DC bias system which relies
on correct electrical performance to attain proper operation of
the amplifier. All transistors tested OK.
The pressure roller had seized on its shaft. I removed the assembly
and cleaned the shaft and the roller surface then lubricated the
shaft and refitted everything. The roller now works smoothly.
I cleaned the audio and erase heads together with the metal tape-bearing
surfaces.
In operation I noticed the main drive belt is so long that mechanical
resonance from the motor can set up oscillation resulting in a
reinforcement of background hum. I drilled the chassis and fitted
a simple damper so that belt oscillation is curtailed.
I cleaned the reel surfaces and cleaned and slightly roughened
the rubber idler wheel. The rubber is starting to craze but is
still pliable and should be serviceable, at least for a couple
of years.
I lubricated the plastic play/wind selector mechanism with grease
to smooth its operation.
Sometimes there is a lot of crackling when first switched on.
I traced this to the mains on/off switch which is lazy in operation.
This should rectify itself with use. Occasionally the indicator
lamp would flicker but this is slight tarnishing at the lamp contacts
and nothing to worry about.
Play appears to be pretty good and the tracks appear to be aligned
correctly for the sample tape provided.
return to customer repairs