Hi all.
I hope that you can help.
Interior unit is displaying; Operation - Off, Timer - 2 Flashes. (Reverse communication error).
No LED's on exterior control PCB.
236Vac in, and at points W4-W5, W8-W9 and TM101-TM102 on Power PCB. 236Vac at CN34 and W10-W11 on Control PCB as expected. All fuses good.
There is 4.15Vdc across W12-W13 (Yellow-Blue to ACTPM). What voltage should I be seeing?
There is 1.7Vdc across W16-W17 (Black-Red to ACTPM)
Serial communication connection connected; something in the order of 20-67Vac.
Serial communication connection disconnected; From interior unit 70-90Vac, from Control PCB -2.38Vac. Inverter tester showing communication in one direction only.
What should I be seeing at CT connection between Power and Control PCB?
I have attached the main current area of the wiring diagram here

At D101, I have 2.54Vac across AC and 1.70Vdc across DC.
At IC's 1,2 and 3 there is only 5.4mVdc across 3 and 5.
I have tried to give as much information as possible, but I would like a more accurate diagnosis as to which component has failed. Obtaining Fujitsu/General parts here can be difficult as the easiest.
Thanks in advance.....
Graham