My Icom u2AT
just like this handheld pictured, was developing a problem in that it occasionally ignored the -600 KHz position of the Duplex repeater switch. It would go simplex. Contact cleaner didn't help. So I decide to do open heart surgery on it, and it was a real PITA to get the various boards and whatnot out of the way to get at the solder side of the board the switch was mounted on. I finally get in there, and found a bad solder connection on one of the switch contacts. Which means that it left the factory in Japan that way. Anyway, I ended up using some rosin solder flux goop to get the solder to flow to make the solder joint from the switch pin to the circuit board hole. It took a few tries before I got it to go. Then reassemble it, wondering if I destroyed something. But the damm thing worked! And the repair seemed to do it, now I can reliably get -600KHz so I can work the machine on 146.955