Working on a Fujitsu aoyg30lat4 with 3 cassettes running off same condenser.
1st repair found communication error and blown controller pcb, meggard compressor and fan motors all ok so swapped board and blew straight away.
Rang Fujitsu and were told to replace fan motor and board it then ran for a bit but only on 1 circuit, rang Fujitsu and was told to try swapping ee valve heads around and then the board blew was told by Fujitsu that it shouldn't as it is low voltage.
We then tried changing all EE valve heads and new board and blew again instantly where the EE valves are plugged into the board.
This unit is less than a year old and Fujitsu don't really want to help and I am lost.
And the customer and my boss are getting annoyed.
Any help will be appreciated.
Thanks in advance
Matt