Acson A5 WM 20GR not starting

Hello,

I am having the following problem with an Acson A5WM20GR - ACIBA Wall Mount Split unit.
It does not turn on anymore, neither from the wireless remote control nor from the button on the indoor unit.

At first the unit did not want to accept any commands from the remote control, regardless of the button that was pressed.
The unit was still operational from the on/off button on the indoor unit.

After removing the unit from mains and reconnecting it, the indoor unit makes one "beep" like it used to do when reconnected to the power supply but does not do anything else. No remote commands, no on/off button commands accepted.

No error patterns are displayed on the internal unit LEDs. In fact no LED turns on.

I have checked the internal fuse and it is OK.
All wiring is intact
Sensors are clean and operational.
I have done a basic check on the IR sender and receiver and they seem operational.

Could you please help with some other troubleshooting ideas/suggestions besides replacing the PCB which proves to be a really tough task since I cannot seem to find it as a spare part (A04084071973 or N31020128) as the unit was produced in 2006.

Thanks in advance for your help.

Change the power board.. I maintained hundred units of ACSON and it working well. Easy to troubleshoot.

Hello John,

By power board you mean the entire electronics unit?
I am having big trouble in finding that component: (A04084071973 or N31020128).

The power source seems to deliver power correctly to the electronics, but it seems like the processor "forgot" the entire programming and just doesn't do anything