I had a similar problem with hitting a 440 repeater with one of my Ic7000s.
The problem was that although I could key the transmitter and power was being sent out the receiver was not working on the 70 cm band.
Do you know you are putting out power?
I assume the transmitter is drawing more current on transmit, but I have a power meter for VHF / UHF but no signal generator to prove the reverse.
Are you putting out power? Can you check with a HT?