Hi guys
Does anybody have the service manual/schematic for the PPI-2300M ?
Won't power up properly. The amp is dual mono, one side SG3525 is missing all of the voltages, the other one is in protect pin 1 is higher than pin 2 at the SG3525. If I force pin 1 to ground or short pin 1 to pin 2 amp starts fine and plays fine, but only 1 of the channels/1 side. The other side/amp is completely dead.
Could not find shorted transistors or diodes.
Pin 2 of the SG 1 is tied directly to pin 8 of the SG 2....so if SG does not get the needed Vcc and and pin 8 ~ 5v, SG 1 won't start at all.
Pin voltages are in attached picture.
There is no DC at the speaker output terminals.
Does anybody have the service manual/schematic for the PPI-2300M ?
Won't power up properly. The amp is dual mono, one side SG3525 is missing all of the voltages, the other one is in protect pin 1 is higher than pin 2 at the SG3525. If I force pin 1 to ground or short pin 1 to pin 2 amp starts fine and plays fine, but only 1 of the channels/1 side. The other side/amp is completely dead.
Could not find shorted transistors or diodes.
Pin 2 of the SG 1 is tied directly to pin 8 of the SG 2....so if SG does not get the needed Vcc and and pin 8 ~ 5v, SG 1 won't start at all.
Pin voltages are in attached picture.
There is no DC at the speaker output terminals.
Attachments
These amps don't like limiting on the B+. Have you tried starting only one half of the amp at a time?
What limiting ? I'm not limiting anything on the b+.
Have you tried starting only one half of the amp at a time? - i'm not 100% sure what do You mean by this...there is a single remote wire going to the both mono amps inside but it's pain in the a** to trace it....
Have you tried starting only one half of the amp at a time? - i'm not 100% sure what do You mean by this...there is a single remote wire going to the both mono amps inside but it's pain in the a** to trace it....
Some of the supplies like I see there have limiters or are limited in current output.
Following pin 15 of SG2 back do you see any resistors or transistors between that pin and pin 15 of the other SG pin 15?
Following pin 15 of SG2 back do you see any resistors or transistors between that pin and pin 15 of the other SG pin 15?
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Fixed the amp....it was a leaky pnp transistor in the whole bunch of gazzilion transistors in the ps section...oddly enough, it was reading fine on my LCR meter, but i've replaced it anyway and this fixed the issue. Just a single MPSA56.
Sorry if I've wasted your time guys,
Sorry if I've wasted your time guys,