zaskarx
Active Member
I picked up a non-functioning CR-2020, it looked great outside but ended up being somewhat of a basket case inside, likely due to heavy use. The main filter cap board had a number of traces that had been roasted off of the PCB and some not so happy caps, transistors and resistors. I replaced all of the bad components (including all electrolytic caps) and performed the service bulletin updates. I made SURE to orient the incorrectly marked cap correctly on this board.
Figuring the rest of the caps were likely in sorry shape, I decided to recap the entire receiver and give it a thorough cleaning. I finally fired it up yesterday on the DBT, everything seemed OK so I plugged it directly in. It was fine for a few minutes, but when I started adjusting the idle current, a resistor on the right output board went up in smoke. It is the 470 ohm resistor right above diode D607, pics are attached.
I'm hoping this doesn't mean that the output transistors are shot, I am planning on taking them out of circuit this evening and testing but would appreciate any guidance/advice from those who are more familiar with the CR-2020 on what else to inspect/check. I can't imagine it is just an isolated bad resistor. Thanks!
Figuring the rest of the caps were likely in sorry shape, I decided to recap the entire receiver and give it a thorough cleaning. I finally fired it up yesterday on the DBT, everything seemed OK so I plugged it directly in. It was fine for a few minutes, but when I started adjusting the idle current, a resistor on the right output board went up in smoke. It is the 470 ohm resistor right above diode D607, pics are attached.
I'm hoping this doesn't mean that the output transistors are shot, I am planning on taking them out of circuit this evening and testing but would appreciate any guidance/advice from those who are more familiar with the CR-2020 on what else to inspect/check. I can't imagine it is just an isolated bad resistor. Thanks!