Flex-6300 no Rx, no Tx

Hi,
Yesterday after months (more than one year) starting up again my Flex-6300. But it doesn't work anymore.
I can connect, I see waterfall, I see audio level if I speak, but I don't see any reception on the waterfall, I have a flat line at around -120db, I don't see any transmission, no SWR no RF Power.

What did I do:
- Connect ANT1 to an end fed Antenna, works fine on a Yaesu 857D
- Connect ANT2 to a dummy load.

Then update SmartSdr from 1.9.13 to 1.11.12.
Did a factory reset.

No change. Pressing PTT and speak, or use AM, or use the TUNE button, no RF output at all.
During TUNE and TUNE Power > 0 the current cunsumption is about 11A. For me it seems thet the RF part is somehow 'disconnected'.

The only mistake I did, so far I know, is that I first had a wrong voltage of 15.4V instead of 13.8. But this is still within the 15% tolerance stated at the data sheet.


Radi S/N: 4914-4175-6300-5953
HW Version: v1.11.12.446

Any hints?

73, de Gerhard
OE1GTC