Picked up a 765 for $175.
Radio had no RX/TX.
Owner said he replaced Q14 driver....
I had the radio on for a bit and RX magically apeared but not on 22-29.9mhz.
Went though the vco chain, rx back all bands.
RX light remained on when PTT pressed, FM static could still be heard when PTT pressed.
Checked Q14, bad solder job, tested it out of radio, made sure it was installed in right direction.
Checked voltages at Q7, no 7.9V on TX. Reflowed solder joints, started tracing the circuit, checking voltages on top side.
Then I seen under a bundle of wires a crispy black resistor, R18 10ohm.
Replace R18, C15 1uf as original C15 was near dead short.
Fired the radio up, complete success, TX and RX even after a cold power up.
This radio is every bit as good as the proIII, maybe better in some aspects.
Just a heads up if anyone owns a 765.
Radio had no RX/TX.
Owner said he replaced Q14 driver....
I had the radio on for a bit and RX magically apeared but not on 22-29.9mhz.
Went though the vco chain, rx back all bands.
RX light remained on when PTT pressed, FM static could still be heard when PTT pressed.
Checked Q14, bad solder job, tested it out of radio, made sure it was installed in right direction.
Checked voltages at Q7, no 7.9V on TX. Reflowed solder joints, started tracing the circuit, checking voltages on top side.
Then I seen under a bundle of wires a crispy black resistor, R18 10ohm.
Replace R18, C15 1uf as original C15 was near dead short.
Fired the radio up, complete success, TX and RX even after a cold power up.
This radio is every bit as good as the proIII, maybe better in some aspects.
Just a heads up if anyone owns a 765.
