One end of R68 goes to both Bases of A1715 and C2814, and the other end goes to the Collector of the A1715 only. R34 has the same connections on the other side of the output driver area. Not sure how the pulldown resistor is supposed to be connected...
R68 reads 5.128k ohms with the probes one way, and 5.025k with probes reversed.
R34 reads identically
R68 reads 5.128k ohms with the probes one way, and 5.025k with probes reversed.
R34 reads identically
That's the pulldown on the base. I wouldn't want to risk changing that value since it loads the driver IC.
The pulldown resistor on the FET side of the driver transistors would likely connect between the emitters of the emitter-follower pair to the collector of the PNP driver (which should also be connected to the source leg of the output FET) of that EF pair.
The pulldown resistor on the FET side of the driver transistors would likely connect between the emitters of the emitter-follower pair to the collector of the PNP driver (which should also be connected to the source leg of the output FET) of that EF pair.
Getting back to this one. The amp is currently functioning as normal without going into protection but just has a problem with running too hot. I tested it in a vehicle for a few days and it played continuously and at times vigorously without going into protection, however the testing was limited by available current and subwoofer power handling so the amp was not pushed close to it's potential limit.
If there is a way to get the amp to run cooler, that would be the fix as it heats up on the output side even when idling with no input.
If there is a way to get the amp to run cooler, that would be the fix as it heats up on the output side even when idling with no input.
When it just starts to heat up, is it heating more under the PS FETs or more under the output FETs?
Were all of the parts replaced with exact replacements?
Were all parts from reputable distributors?
Were all of the parts replaced with exact replacements?
Were all parts from reputable distributors?
Heat is coming from the output section. All parts were the exact same part numbers (PS FETs and outputs) and purchased from Mouser.
There was some burnt/damaged areas of the circuit board at the gate leg of one PS FET and at the legs of two PS driver ICs, but substitute connections were made and I don't believe there is any conduction from those areas. I was thinking that PS issue was a non-issue due to the stable ±rail voltage, the amp operating without protection and that the heat is from the output section.
There was some burnt/damaged areas of the circuit board at the gate leg of one PS FET and at the legs of two PS driver ICs, but substitute connections were made and I don't believe there is any conduction from those areas. I was thinking that PS issue was a non-issue due to the stable ±rail voltage, the amp operating without protection and that the heat is from the output section.
Do you have a FLIR imager?
Does it heat up at idle?
Did you look at the individual gate signals on the outputs to confirm that all were good?
Does it heat up at idle?
Did you look at the individual gate signals on the outputs to confirm that all were good?