Rock-Ola 1494 no sound from right side

[gordo]

Hi All,

I just bought a 'new' project jukebox. It is a Rock-Ola (stereo) 1494 and it has had a very full life, but I hope to save it.

Unfortunately there is very, very low output from the right speaker. The left side is OK but not great.

I contacted the seller and he advises me that the amp was just rebuilt by a professional Audio business before he sold the jukebox. He provided the business name. 

I called the repairer and they are adamant the problem will not be in the amplifier. They are not very helpful and unfortunately a long distance away.

I am not able to find anything obvious. I tried switching the speakers etc, but no change.

Before I ship it out to another repairer, is it possible I may be missing something?

Anything else I should check? Inputs, volume controls, power?

Any suggestions greatly appreciated.

Kind Regards

Gordon...

[Ron Rich]

Hi Gordon,
Sure--swap inputs--could well be a poor cartridge-- also check volume control. If no change, it's the amp-- if tube (valve) type, swap tubes--
Ron Rich

[gordo]

Thanks Ron,

Yes, tried your suggestions without any change.
I guess I will need to send off to another repairer.

Kind Regards

Gordon...

[Ron Rich]

Hi Gordon.
Is there a "balance control" on the amp--does turning it change things ?
Ron Rich

[gordo]

Hi Ron,

Yes there is a balance control, but it does not help.
It reduces the volume from the good side, so then there is no sound at all.
No sound from right side.
I swapped the cartridge wires from side to side.
I swapped the volume control wired from top to bottom.
I swapped input from the cartridge from side to side.
I swapped the valves from side to side.
No change.
All the caps appear brand new, so I suppose the technician changed them.


Gordon..

[Ron Rich]

Gordon,
IMHO, you have proven the amp has a fault---
Ron Rich

[gordo]

Ron,

Thanks for your time.
I am taking to someone I trust.
I will let you know the outcome.
Regards

Gordon..

[gordo]

Hi Ron,

I took the amp to a reputable technician (guitar guy) who fixed the problem.

For your information this is what he said....

"I found a fault at the first tube that the right input signal sees, that being an open circuit plate resistor which means the right channel triode won't power up and and so no output".

Easy fix if you know what to look for.

Thanks again for your patience.

Now, on to the rest of this very worn out jukebox.

Regards

Gordon...

[Ron Rich]

Hi Gordon,
Thanks for this post--makes sense--enjoy ! Ron Rich