Ok. I've fitted new bs170's and rewound the RWTS transformer. Further testing shows no sign of any clock signals at all from the 5351 which would explain the complete lack of RX. It may also explain why two of the bs170's were getting toasty on key-down. I had initially suspected a short in the output transformer but, in hindsight, I would have been able to detect even a small amount of RF if that had been the case.
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Could the failure of the 5351 have been caused by the initial fault with the 3.6v zener on the 3.3V board? If so, are there other parts likely to have also succumbed?
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I'm not sure how much time I can justify putting into this but I would like to get it back on its little feet again. Any suggestions, pointers or advice would be welcomed at this point.
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Cheers,
Ronan?
MM0IVR?
