ICOM R-75 Repairs

For that item specifically, not me, but what are you having trouble with?

The receiver suddenly went deaf. All control functions work. It’s almost like it went into RF mute and got stuck. Audio however is not muted. Keypad beeps are heard and still controlled with the AF level control.

@lothar Is there any static or is it completely quiet? If there is static, based on the pictures I saw, it could be related to the attenuator/relays (I am guessing they are for that). If it is fully quiet except for input beeps, I would say oscillator or IF has an issue but it could be deeper than that. I haven’t worked on a digital radio like that, based on traditional radio theory that is what I think.

@radtekman  Completely quiet. And I just noticed the DSP is on full time now. Someone else suggested removing the DSP option as a test.

@lothar I would say anything is worth a try. If it still doesn’t work, then it just points you in another direction. Not sure what kind of equipment you have, but using a signal tracer, scope, or spectrum analyzer could tell you if the oscillator is running to rule that out.

I do have a scope and a spectrum analyzer. Just trying to eliminate the simple things first. CPU reset didn’t do anything. I’m going to remove the DSP board next.