so this has been bugging me for about two weeks now and im at a loss. my 7300 just randomly started having terrible receive sensitivity, like i can barely hear anything on 40m that i used to be able to copy easily. transmit seems totally normal, did a quick check with a dummy load and my power output looks right, swr is fine. but receive is just... dead feeling. not completely silent, just way down, like maybe 20-30db down from where it should be.

i swapped antennas, tried a completely different feedline, even hooked up my old dipole directly at the radio just to eliminate the line and connectors. no change. the noise floor looks lower than it should too on the waterfall, which to me says it's upstream of the SDR section, maybe preamp or the front end somewhere. ive had the top off and nothing looks obviously burnt or damaged, all the connectors on the board look clean. did the basic reset already and it didnt do anything.

anyone else seen something like this on a 7300 or know what i should be checking next? wondering if maybe the LNA blew somehow or if theres a known failure point on these. been lurking here a while and figured someone might have run into it.

had almost the exact same symptoms on mine about a year ago, turned out to be the RF input relay. those small signal relays that switch between the antenna and the internal attenuator/preamp path can get flaky, and when they do the receive tanks but tx is routed differently so it still looks fine. icom used a pretty standard relay there, nothing exotic. you can actualy hear it click when you key up if you listen close.

the way i confirmed it was to probe the relay contacts with the radio in receive mode and wiggle the board slightly near that area — got intermittent noise changes which pointed right at it. if youre comfortable with SMD rework it's not a terrible job to replace, just takes patience and a decent iron. if not, icom service centers know this failure and it shouldnt be a huge repair bill. worth calling around for a quote before you dig in yourself.

dont rule out the IPO/preamp switch itself getting stuck in a weird state. i know you said you did a reset but have you actually gone into the menu and manually toggled the preamp off and back on, and same with the attenuator? sometimes on mine after a firmware hiccup it would show preamp on in the menu but it wasnt actually doing anything. probably not your issue if the noise floor is visibly lower on the waterfall but worth 30 seconds to rule out.