Discussion in 'Tuners' started by mea2112, Apr 12, 2018.
I was thinking the same to jumper out the PIN diodes in the front end.
Thanks again guys. I guess I have some catching up to do!
Would one of you great teachers mind explaining how I could go about jumpering to the front-end to check the PIN diodes?
Short D3 anode to D4 cathode, connect your antenna to "A",test
D3 and D4 are under copper-colored shield I'm guessing. How do you get that dang cover off? Best (only?) way to short D3 to D4?
I am not sure exactly how to dis-assemble the shield cover since I do not have one nor have I serviced one in the past. Sometimes they are friction fitted, in some cases they are soldered. Use a jumper wire with some grabber clips on both ends to apply the short.
Thanks. Power Supply test points measured -12V and +12.39V
Finally got the shield cover off. Internal A/B antenna parts appear to be undamaged.
On to the D3/D4 diodes. Man, they are tiny! Like 3/16"? My small grabber clips are too big to grab onto the anode/cathode. Any other suggestions?
Also, the point of shorting D3 and D4 is to bypass them or essentially remove them from the circuit right?
With power off you can do a DMM diode test on those diodes to see if they measure okay. D1-8
need to get smaller grabber clips to get at the leads.
You can also access the diodes from the solder side of the pcb.
That is correct. You do not know if the diodes are open, short or okay, have to check them out.
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