so this has been sitting on my bench for about three weeks now and im finally getting around to posting about it. we had a pretty bad storm come through in late september, nothing hit the tower directly as far as i can tell but something must have come in through the coax because my 7300 just... stopped receiving. transmit seems okay actually, i can key it up and the power output looks normal on the wattmeter, SWR reads fine too. but receive is just dead, like completely silent no matter what band or mode i try. not even static.

ive already pulled the antenna connector off and tried a dummy load on the receive side just to rule out the obvious stuff. also checked that the preamp wasnt doing something weird, turned it off and on, changed settings back to factory, nothing. the RF gain is up, AF gain is up, its not muted. its genuinely just silent.

my first instinct is the front end got cooked somewhere between the antenna connector and the first IF stage but i really dont know where to start probing on this thing. anybody had a similar experience with these or know which part of the signal chain typically takes the hit in a near-strike situation? i have a service manual but the block diagram is only kinda helpful without knowing what im actually looking for.

yeah the front end on these SDR-based rigs is really vulnerable because there isnt the same kind of filtering ahead of the ADC that older superhet designs had. the 7300 has a band-pass filter board before the RF amp stage and that whole area is worth a close look first. icom uses some TVS diodes for transient protection in there and those will sometimes sacrifice themselves to save the more expensive stuff — which is actually good news if thats what happened because replacing a DO-214 TVS is pretty straightforward.

the thing i would do first is pull the top cover and look for anything visually obvious, burned traces, a component that looks discolored or cracked. if you have a DMM do a diode check across the protection components near the antenna input and see if anything reads like a dead short. if the TVS sacrificed itself itll probably show as nearly zero ohms in both directions. the RF amp IC itself (i think its a fairly common dual-gate MOSFET in that stage but dont quote me) can also get nuked, those are harder to source but not impossible. dont let the service center quotes scare you off if the damage is actually pretty localized, sometimes its a ten dollar fix after a forty dollar part hunt.

had almost the exact same thing happen to a friends FT-991 a couple years back. turned out one of the band filter relays had actually welded itself shut from the transient and was routing signal into the wrong path entirely. transmit still worked because the TX path went around it somehow. might be worth checking the band switching relays too if the TVS stuff checks out fine, just something to keep in mind before you go too deep into the RF amp section.