Working on an old Alpine 3555.
Got the PS and the regulator stabalized.
Rail ( 10V B+ input) is +/- 23v.
Outputs are not in circuit.
NPN output has -20v on the base pad.
B -20v C 16v E 0v
PNP
B -21v C -23v E 0v
The -20v on the NPN base --drive IC *02 bad? Same on all 4 channels.
Got the PS and the regulator stabalized.
Rail ( 10V B+ input) is +/- 23v.
Outputs are not in circuit.
NPN output has -20v on the base pad.
B -20v C 16v E 0v
PNP
B -21v C -23v E 0v
The -20v on the NPN base --drive IC *02 bad? Same on all 4 channels.
Attachments
The servo/feedback circuit may simply be trying to compensate and it can't because the outputs are out of the circuit.
It's strange to see only 16v on the collector. It should be 23 from what you posted.
Why don't you have the outputs in the circuit? You can't troubleshoot the amplifier circuit using voltage with the feedback loop open.
It's strange to see only 16v on the collector. It should be 23 from what you posted.
Why don't you have the outputs in the circuit? You can't troubleshoot the amplifier circuit using voltage with the feedback loop open.