First time on here so be gentle

Have a Carrier Chiller RA 30

Comes up with an Error 34 fault as far as I can work out, this is a reverse rotation fault thrown up by sensors not picking up a difference in pressures.

The compressor does not even try to start just goes in to fault

Sensors on Pro Dialog are reading correctly and do change readings when compressor is helped to run

Checked Hp switch this is made , checked connections to the board all correct

Anyone have any ideas or is it time to call in a man with a laptop

Thanks