I have just replaced the front panel PCB on a friends FT817ND (Lot82).
I had called Yaesu UK and the told me that the board was compatible (CS1909409).
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It was a straightforward replacement except for desoldering the AF-SQL/RF pot.?
I had to snip the pins of the old connector to remove it but I do not believe that I damaged the pot and it seems to test ok.
On powering up the LCD screen display blinks and there is no audio.? I am able to change frequency, mode, etc and all buttons and dials seem to work.? However, the ?AF-SQL/RF pot does nothing.
Searching the web I am told that this is clasical of the PLL not locking.
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I plugged in the original board and this seems to lock (PLL wise).? I have no screen (reason for replacement) but using 'FT817 Commander' software I can 'see' the frequency, mode etc and all seems to be well on the receive front.? Audio is working.? The radio shuts down when I try to transmit but this may be RF getting in somewhere it shouldn't (the whole radio is out of its container).
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I obtained all the parameters from the service menu on the original board and programmed it into the new one hoping that this was the answer.? No difference.
I presumed that I would have to do a full alignment and I started this.? I did not get very far:-
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Reference Frequency Adjustment - No problem - freq and voltage fine.
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VCO VCV Adjustment - voltage wrong and not adjustable as PLL not locked.
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PLL "Unlock" Display alert - unplugging the Ref Unit the voltage is 5mV on J2002 (pin1) but no change in the display.? The voltage is 25mV with the unit replaced.
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2nd Local Adjustment - No problem
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3rd Local Adjustment - not possible as no transmit
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And thats as far as I got.
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Am I missing something?? Is this board really compatible?
Is there something specific that I need to alter (pot,menu item etc) to allow the PLL to lock.
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Any help gratefully received. Thanks.
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Best wishes,
David G7IBO
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David