Outdoor Daikin unit does not start

[daikingrech]

I own a Daikin FTX35J / RX35J airconditioning unit and am curreently facing a problem taht the out door unit does not start at all.
The indoor unit starts fine, but there is no cooling.
The outdoor unit does not start up at all. Neither the compressor nor the fan of the outdoor unit are starting up.

there are no error messages on the remote control. Also when checking for any errors ( by pressing the CANCEL button on the remote control and cycling through the error messages - the continuous beep is only heard on the 00 code which when checking in the service manual it relates to Normal condition).

All teh 4 LED's on the Invereter card ( of the outdoor unit) are OFF - hence displaying no errors - but the LED-A of the outdoor power supply unit is not blinking - according to the manual it is supposed to be blinking.

After following the electrical circuitry I noted that the relays MRM10 and MRM20 and MRL are not being activated - hence blocking any electrical current from reaching the rectifiers and transistor module - hence never reaching the compressor or the fan.

Checked the resistance of thermostats and their resistance is changing with temp. I immersed them in ice and the resistance went up to about 67k, whereas at room temp the resistance is around 16 to 20k. According to the service manual this is more or less within range.

Does anyone have any idea what might be wrong?
It seems that the HIC electronic module on the Inverter card ( (code: 3EB19045) is awaiting some conditions to be able to switch on the relays - but I cannot decyfer what could be wrong.

Can anyone help me out debug this problem please?

Thank you.

[ork20]

hi there,if the indoor unit is running and there is power to both indoor and outdoor units then u may have a communication problem. This is fairly common on new installs when the interconnecting wiring between indoor/outdoor, the neutral and the controll cable are swapped round at some point eg spur. Try tracing the wiring back to see what u find.

[daikingrech]

Thanks Ork20. The airconditrioner has been installed for a couple of years and it has been running fine in the past. It just happenned that this summer as soon as I tried to start it up I discovered this fault. I changed the wire already however still the same sympthoms are occurring. In fact I disconnected the signal wire and noted that with the signal wire disconnected, not even indoor unit wil start and there will be an error U6 on the remote ( when jogging through the error list). So following this I have excluded the wiring issue.
Does anyone think that with such symtoms the Invereter PCB is at fault?

Thanks.