Re: Amplifone HV board

> Mark Jenison wrote:
> >
> > What does the red LED on the HV PCB indicate? It is currently lit.
> >

That means that the over voltage protection circuitry has cut in. If that LED is
lit, you are no longer getting any HV because theoretically, the protection circuitry
has turned it off. You need to power down the system to reset the circuit.

I once had a problem like this. It turned out that I did not have the grounding
(DAG) wire connected. My monitor didn't work at all without this grounding wire
attached. Verify that yours is connected just to be sure. It's not actually that it
matters that the ground wire is attached, is just that the molex connecter that
connects the wires has a jumper wire on it that is used to jumper two wires together
in the molex shell. I forget now which wires they are, but if the jumper isn't
present, my boards didn't operate. I do not know if different revisions of the HV
board behave differently.

Having the HV set too high will cause the over voltage circuit to activate. Make
sure that the HV pots are set on the low side then just in case the over voltage
circuit is getting tripped immediately, due to too high of a setting. Normally, this
wouldn't happen, because when you initially get the board running and you fine tune
the voltages, you set that pot once, and leave it alone. Any idea if the board ever
worked since it was worked on?

Joel-
Received on Wed Sep 30 16:11:04 1998