Dometic RMD8505 Not working on gas

[Toffeebananas]

Hi,

Thought I would post just encase I can help someone in the future which has the same problem as I have had.

My Dometic Fridge Freezer RMD8505 would not work on gas. Its a 2017 MY so fairly new. After doing a few basic checks -

Is the van level, is there gas in the tank, have I bled the lines as best as I could (lit hob), does the fridge work on 240V/12V.

All of the above were yes.

My next check was, am I getting ignition? After setting the fridge to gas, I checked outside at the back of the fridge to see if I was getting a spark at the electrode.

No spark at the electrode and the fridge just faulted out again.

As there is no spark, it ruled out an issue with gas supply, burner nozzle blocked, or flame detection electrode.

I reset the fridge and tested with my multi meter at the control unit on the back of the fridge where the electrode plugged in. No power coming out of the unit to the electrode when it should be trying to ignite.

I was then advised to change both the, PCB at the back of the fridge (sometimes called the 'brick'), and the main control unit on the front of the fridge.

I made the decision to change the brick first. This unfortunately did not fix the problem. I then changed the control unit on the front of the fridge. Presto! This resolved the problem!

To my surprise it looks that my problem was all down to the main control PCB on the front of the fridge. The one which sits between the two doors with all the selection buttons. Something I did not expect from a fridge a couple of years old.

 

Changing the PCB at the back of the fridge was fairly straight forward mostly just plugs to unplug and re plug into the new PCB.

Changing the PCB control on the front of the fridge was a little more tricky to do it properly.

 

 

[onecal]

What caused the PCB to fail?

Was it condensation?