After trying alot of things to fix a drift issue which helped but did not quite cure the issue I decided to rebuild the lvps section of the AF-AVR board and also incorporate
a modification that is out there on the web shown here :
After changing the zener, and putting in new resistors from C-E I didnt have any 9V output from the board anymore when put back into the chassis.
I removed it and tested on my bench with a 16.5VDC input to L5 and it seems to more or less work when I apply a load to the 9V line, however when I vary
VR4 the 9v level does not vary. I had seen that vary and adjust the 9v output back before I began the work, so I know the pot works.
At one point I had the test voltage applied backwards during my bench tests, but I dont think I left it on long enough to do harm, as there was no smoke coming from anything.
When it was first installed into the chassis, and dre current I did smell a resistor burning so I had shut it down. The smell seemed to come from near where the 9v is generated,
but cant see anything obviously burned. Attached is a pix of the lvps and theres a llink to the entire schematic of the radio.
I did notice I have 49 ohms to gnd when the board is installed from the post marked (12) which is the collector of Q34. Thats kind of a low reading
and I see it runs back to the main power supply board to a relay but I dont understand what that relay is doing. The 12V also seems to go to the PLL
board and one other location, but 49 ohms seems strange, unless there is a short on the transistor now after putting the mica insulator on the new transistor.
Any feedback or comments appreciated on how to confirm the issue appreciated.