Re: Front panel troubleshooting


The Logic Board is repaired and seems to be working fine. Replaced the CPU, serial EPROM, and the 3.3 volt regulator that supplies the keep alive circuit. QC-ing the CPU, a 144 pin chip, was a bear. In the end had to check each pin with one needle probe on the board land and the other LIGHTLY on the pin where it enters the chip. Found at least a half dozen poorly soldered pins (my work) that had intermittent or no connectivity.

After that the display worked and I could hear but only really strong signals. Turns out prior work (not mine) had scraped a capacitor  in the first IF circuit off the board and I was losing about 30 dB of signal on everything but WFM mode which worked normally. Replaced the 0402 smd and now the receiver shows S9 or better on all bands with a -73 dBm input signal and all modes work. So far so good...... it is coming back to life.

Next TRANSMIT. So far it goes into transmit mode but no power at all out on HF/6M, about 2.5 watts out on 2m, and less than a watt on 450. Not out of the woods yet but very promising.

Warren - WA8TOD

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