so i've had this 706mkiig for years and its been rock solid until lately. started acting up about a week ago. works fine on 2m but when i switch to hf ssb mode it keys up (can hear the fan change) but power meter shows nothing. fm on hf works fine though. already cranked the mic gain way up and that helps but seems like something else is going on. anyone else seen this before? really dont want to ship this thing off to get fixed if its something dumb im missing

had the same exact problem with mine a few years back. turned out to be the ALC circuit acting up. you might want to check the alc voltage while transmitting in ssb - should see some deflection on the meter when you talk into the mic. also make sure your processor settings are right, sometimes they get messed up and the radio thinks its overdriving when its not. mine needed a cap replacement on the main board but that was after like 15 years of use

check your power supply voltage first before you do anything else. those 706s are really picky about voltage and if its dropping under load in ssb it might explain why fm works (less power draw). also wiggle the power connector - the molex one they used is notorious for getting loose connections. if that doesnt fix it then yeah probably needs to go to a tech but at least you ruled out the easy stuff first