After this, his Horus doesn't power on with the power button at all. He says the radio does power on when he unplugs and plugs the battery in again. When that is done, the radio works fine until power off. But after he switches the power off (with the power button), his Horus doesn't turn on anymore until the battery is reconnected again.
He checked the internals and says the U14 looks suspicious:
Can it be related to the power on issue?
Unfortunately, the marking on this IC is not very readable...