so ive been fighting this thing for about two weeks now and im starting to lose my mind a little. picked up a used 7300 from a local guy, seemed fine at first, but i noticed the power output is just... soft. like running 100w into my wattmeter and the meter shows maybe 28-32 depending on band. doesnt matter if im on 40 or 20 or 10, its always in that range. ALC looks okay on the display, not pinning, drive is set to 100%, RF power knob is at max.

already went through the obvious stuff - checked the coax from the rig to my meter (swapped cables to confirm), confirmed the wattmeter is accurate with my other radio, did a factory reset just to see. nothing changed. the radio sounds clean on receive, no weirdness there. transmit audio reports are fine from other stations.

i did notice the finals area gets a bit warmer than i'd expect but not crazy hot, and there's no fault indicator or anything popping up in the menu. starting to wonder if one of the PA transistors is partially gone or if theres something upstream limiting drive to the finals. anybody dealt with this before on a 7300 or similar SDR-based rig? not sure if i should crack it open and start probing or just send it to a service center.

that symptom pattern with no fault indication and no thermal shutdown points me toward the driver stage before the finals honestly. on a lot of these radios when one final goes soft you still get some output but you lose the full swing. 28-32 watts with the knob maxed is actually kind of a classic sign that the drive level is making it to the finals okay but something in the PA chain isnt amplifying correctly.

before you start probing around in there id check if Icom has any service bulletins for that serial number range, some early 7300s had known issues. also worth pulling the bottom cover and just looking for anything obvious - scorched components, a cap that looks like it bulged, cold solder joint on the PA board connector. ive seen cold joints cause exactly this kind of degraded output with no other symptoms. if you have a scope you can probe the drive signal going into the finals and compare it to what you should see in the service manual, that'll tell you pretty quick if the problem is upstream or in the PA itself.

had almost the exact same thing on a friends 7300 last year. turned out to be a partially failed RD70HVF2 in the final stage. one of the pair was still conducting but way degraded, so you get output but nothing close to full power. radio had no idea anything was wrong which was the annoying part. ended up replacing both finals as a matched pair, problem went away. parts arent super cheap but its not a nightmare job if youre comfortable with SMD and have a decent iron with temp control. just make sure you get the thermal compound right when you put it back together or youll be right back where you started.