I have an old school Rockford Fosgate Punch 75 with internal 15amp fuses.I am getting DC voltage out both channels I have checked all driver and output stage transisters with my trusty Simpson they seem to be fine.
I am thinking it is going to be a bad op am there are three in these old amps how do I know which one is the culpret.
I am thinking it is going to be a bad op am there are three in these old amps how do I know which one is the culpret.
Well I thought I would get some quick help on here . I will start by replacing the one clesest to a burnt 100 ohom resistor. It is most likely the culpret .
When I replace these op amps I always like to solder a socket in place of where the IC sits so I can easily replace it if I fry the new IC.
When I replace these op amps I always like to solder a socket in place of where the IC sits so I can easily replace it if I fry the new IC.
After Measuring the DCV on both channells
After measuring the DCV coming out of both chanells I found the voltage to be positive +-23 volts from the Orange wire to the black wire and a negative +-23 volts from the yellow to the Brown .
Keep in mind these amps use reverse wiring to bridge the amp.Between the two Hots or the bridge mode I found no voltage.Which means the negative voltage I measured was really a positive voltage. I hope I put that right.
After measuring the DCV coming out of both chanells I found the voltage to be positive +-23 volts from the Orange wire to the black wire and a negative +-23 volts from the yellow to the Brown .
Keep in mind these amps use reverse wiring to bridge the amp.Between the two Hots or the bridge mode I found no voltage.Which means the negative voltage I measured was really a positive voltage. I hope I put that right.
Check the D40D8 and D41D8 drivers to see if they are shorted.
Check the fuses with a multimeter, and check the fuse holders to make sure there is good contact between the fuses and receptacle and to the board.
You could have a bad op-amp but usually you will have no audio if that's the case.
If this amp is using fuses in the speaker harness check them as well.
Check the fuses with a multimeter, and check the fuse holders to make sure there is good contact between the fuses and receptacle and to the board.
You could have a bad op-amp but usually you will have no audio if that's the case.
If this amp is using fuses in the speaker harness check them as well.
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