Vintage HiFi Audio Forum

Repair / Help Forum => Repair / Help => Topic started by: fhawk618 on December 29, 2010, 03:44:33 PM

Title: Carver PM 1.5 that won't quit--won't power off
Post by: fhawk618 on December 29, 2010, 03:44:33 PM

I bought a whole bunch of Carver PM 1.5 amps, and one of them will not power off via the front panel switches. Amp works fine other than it will not turn off--you have to unplug it or turn off the power source. I have checked both switches (Power and Sequencer) with a meter, and they are both fine. Any suggestions on where to look next?

Thanks!

Title: Re: Carver PM 1.5 that won't quit--won't power off
Post by: OCCD on December 29, 2010, 06:49:14 PM

Check the board the fan is wired to. I believe the shut off is  associated with the amp being cool. If there is a problem, it will not shut down.  I just pulled mine apart to install a new fan. When I tried to power it down, it would not go off. Replaced the fan, cleaned the amp, wiggled components on the boards for the fan and power, it now shuts off.  Did you get those amps from the guy in Philly?

Title: Re: Carver PM 1.5 that won't quit--won't power off
Post by: confused on December 31, 2010, 07:00:53 PM

fhawk618,

If the switch has a small bypass cap that shorted, your switch will not turn it off.  A common arrangement on amps to supress noise spikes during switching.

Dale

Title: Re: Carver PM 1.5 that won't quit--won't power off
Post by: fhawk618 on January 01, 2011, 02:17:23 PM

Bought 80 of these amps from a big production company in NY that was swapping them out for new equipment--they actually had over 200 of them available. I've gotten several responses on a couple of forums indicating an issue with the power regulator board--that's the board that the switch and the fan control board attach to. Thanks for your help.