RM ITALY KL-503 HELP PLEASE !!!

[basstracker1970]

I have a rm Italy kl-503 amp and now my preamp isn't working correctly. When I turn on the preamp my signal drops down to nothing and when I turn it back off it goes back to normal. But it defintly isn't boosting the signal like it use to do it kills it now. Thank for any help....

 

[Robb]

IIRC, there is one transistor, 2 diodes, and the switch that run that circuit.
Start by cleaning/working the switch.

 

[basstracker1970]

This amp is fairly new and I have been rocking the switch with no fix. I think its the transistor ,diodes. Can you tell me where the diodes and transistor is locater.

 

[Robb]

Can't find a schematic for it on the net. Did you spray any cleaner into the switch first? ExitThirteen or others may know the answers you seek; give them a chance to read this thread. Or, you can follow the traces from that switch to those parts; that can do it if you are patient. Clean that switch first - though . . .

 

[camaro1]

here it is

 

[Robb]

here it is

OK . . . cool . . .

Looks like this is SMT stuff.

D14, 15, and 16. TR3; an NPN. Relay #2.
They will need to be checked/tested.

Not that familiar with amps; but that is where I would look.

 

[9C1Driver]

In the end don't get too concerned if you can't fix it, 80% of the time a pre-amp is a waste of time. Most of them just bring in more noise and static.

 

[RatsoW8]

In the end don't get too concerned if you can't fix it, 80% of the time a pre-amp is a waste of time. Most of them just bring in more noise and static.

They amplify everything there including noise. So unless you have some excellent NR circuitry on your radio a pre-amp isn't much of a benefit.