Daikin U4 fault

[cool_tech]

Hello guys
Looking at a daikin fxts80gmvba. First fault was F3 so i changed discharge sensor outdoor sensor.
Tried to run next fault was U4 fault.
Any ideas im thinking the board?
Thanks LJ

[Keza]

Try unpluggging the outdoor fan motor. Then start unit up again. If comp starts to run then faults out with fan fault it's the fan. Also could be outdoor pcb like you suggested. Or Both, one could have taken out the other.

Cheers, Keza

[Greek_engineer]

It is sometimes confusing error.it might be the comp or the pcb or the outlet fan....who pays for all these parts?

[Blata]

Basics first you do still have power to the outdoor unit
Check comms cables are connected