Mitsu a/c

[sheao]

i have a mitsu air con fdcva 251 hen inverter it was installed 3 years ago i did have fault code of e5 comunication error.since this error i have replaced the indoor power pcb and outdoor control pcb there is no fault with controller and all wiring has been checked over and over!!but have a communication error of 04 9f with the words wait o9n the controller(this usualy happens when you first switch power up air con for first time)i have the green led on inside unit flashing but no red led flashing does anybody have any ideas?????????????

[BritCit_Juve]

Is the comms wire going through any switch contacts? if so make it continuous.

Wire 2 to wire 3 should have a fluctuating reading of between 2 and 20v dc when system is switched on. If you don't get any reading then the outdoor pcb is dead so check the live and n onto the main pcb, check the pcb fuses and try disconnecting the fan motor (turn power off first).
If you get a steady state of 20Vdc their is a break in the cable between indoor unit pcb and outdoor unit.
try running a tempory cable through to replace wire 3 only and does this sort the problem if so look for a problem with the cable - interference etc.
Brit