Does this DCV across 14 and 16 change with a speaker or other load connected across the speaker terminals?
Do you have a 9v battery?
Do you have a 9v battery?
I do have a 9v battery and a way to put a load on the terminals
The amp still does not have output fets installed, will that affect that troubleshooting method?
The amp still does not have output fets installed, will that affect that troubleshooting method?
Touch the 9v battery across the high-side filter capacitor.
CE2 ad CE4. Do they charge to 9v and hold it for (at least) a short times (minutes)? Don't hold the probes on the capacitor since the meter will discharge the cap. Check it just after charging and every couple of minutes, afterwards.
Did you ever have outputs installed with D33 and R157 out of the circuit?
CE2 ad CE4. Do they charge to 9v and hold it for (at least) a short times (minutes)? Don't hold the probes on the capacitor since the meter will discharge the cap. Check it just after charging and every couple of minutes, afterwards.
Did you ever have outputs installed with D33 and R157 out of the circuit?
They charge to 9v but immediately drop to 1.2v (even pulled one off the board and got the same results)
And no I've never had D33 and/or R157 pulled with output fets fitted
And no I've never had D33 and/or R157 pulled with output fets fitted
Are those capacitors leaky (electrically).
Some of these ICs can be temperamental (or just mental). If they don't start normally, they can cause problems. Some require pre-charging of the high-side supply and to do that, the low-side FETs must be driven on (by the design of the circuit and its start-up sequence).
Some of these ICs can be temperamental (or just mental). If they don't start normally, they can cause problems. Some require pre-charging of the high-side supply and to do that, the low-side FETs must be driven on (by the design of the circuit and its start-up sequence).
I believe they aren't leaking electrically. Should I reinstall D33 and R157 as well as low side fets to see if I get drive?