Hey Perry...(and everybody)
I did finally resolve the problem with this PCA 1500D.
Make a note of this guys !
After a lot of examination, I began to suspect the protection circuitry. I found some mislabelling
on the schematic which added to my confusion. D321 (schem)is actually D320. D322 is actually D321.
the 1N5818 diode between R315 and D3307 which is not labelled, is D332.
When I traced these circuits out electrically and physically, I noticed a tiny solder blob on the bottom side of the PC board connecting the "PC" line off of the Bridged2 circuit to the ground side of C351. The "PC" line connects to the cathode of D307 (which runs to the Soft Start pin of the 3525) The lead of C351 was bent over neatly and soldered so it looked "factory" and it was !!
Once I corrected the problem, the amp no longer went into protection with the RCA's connected. There was no 5 volts on the RCA shields with respect to DC ground either.
Thanks for your help,
I did finally resolve the problem with this PCA 1500D.
Make a note of this guys !
After a lot of examination, I began to suspect the protection circuitry. I found some mislabelling
on the schematic which added to my confusion. D321 (schem)is actually D320. D322 is actually D321.
the 1N5818 diode between R315 and D3307 which is not labelled, is D332.
When I traced these circuits out electrically and physically, I noticed a tiny solder blob on the bottom side of the PC board connecting the "PC" line off of the Bridged2 circuit to the ground side of C351. The "PC" line connects to the cathode of D307 (which runs to the Soft Start pin of the 3525) The lead of C351 was bent over neatly and soldered so it looked "factory" and it was !!
Once I corrected the problem, the amp no longer went into protection with the RCA's connected. There was no 5 volts on the RCA shields with respect to DC ground either.
Thanks for your help,
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