Well this certainly sounds like quite an odd problem. Telling me that
sometimes it comes back on with the crackle of the flouresent light or a
selection being made brought only one thing to mind, and this is
dependent that you are correct that it is the flickering of the bulb,
and not any vibration that sometimes makes it work. The speaker
overload circuit. I've had trouble with them only a handfull of times,
but it is a sesitive circuit and could possibly be affected by small
voltage spikes from the light lighting or the solenoid action of the
selector enough to make it work again. I hope you have and can read the
amplifier schematic, you will need it!

--
Tony


Paul Smith wrote:
I hope someone can help me with an extremely annoying problem I am
having with a Rockola 443. The problem is the sound keeps cutting out
but there seems to be no pattern at all to this. For example it might
work okay for a while when it is turned on then the sound will stop,
other times it will select okay when turned on but no sound then at
some point the sound will start.

I think the amp is okay, checked across the filter caps for voltage
and at any time I will get hum through if I touch the cartridge
inputs. The cartridge is okay also as is the mute relay.

The strange thing is that if a selection is playing with no sound I
can make the sound return by:

Twisting a lamp so that there is a crackle through the amp
Sometimes making another selection (after the number button is pressed
the sound starts)
Playing with the connectors (although a different connector each time
- not one specific connector)

When I do one of these things the sound might come back on for quite
some time then drop out or it might only come on for a short time.
Sometimes it will come on crackly and low volume other times it will
be clear and normal volume.

Could this be some sort of grounding problem or something? I hope I
have explained this okay, even though I am a novice I just can't
narrow down what it might be or where to start.

Really hoping someone might be able to point me in the right
direction.

Paul Smith
Australia