dometic 2018 fridge

[gilly2022]

Hi all...gone camping and the fridge not working at all. The model is Dometic dmr702 and I've checked all fuses ( I think), power to the outlet, and tested some lines in the back of the fridge. I don't have any spark or gas. We have gas through the stove, water and furnace. I have the panel lights working and can change modes and can turn them off and on. No interior light though and I've turned the thermostat up to the highest. We haven't used the trailer for 2 years due to covid so it might be dirty but the trailer is a 2019 and only used it a few times and it was fine. I'm gobsmacked... tried everything I've seen on the internet to do next to buying a new circuit board ( $300 ugh! ). Any help would be greatly appreciated.. thanks so much.. gilly2022

[Old-Biscuit]

On the lower circuit board

P6 terminal is DC+ to the interior light....switch closes making up the Ground side of circuit
*Check Switch & verify bulb is not burnt out

As for the Gas function
The J1 8 pin connection on center of circuit board controls the DC+ to the Gas Valve Solenoid & Spark Electrode

DC+ goes to Pin #6 (bottom row 2nd from left)
DC+ goes to/thru 2 thermal fuses (one in-line behind burner area then up to/thru Switch on Burner stack) from Pin #2 (top row 2nd from left)
DC+ goes back to Pin #3 from stack switch
DC+ goes from Pin # 4 and returns to Pin #8 for Gas Valve Solenoid
*Pin #7 goes to Ground Terminal Screw (grounds for Interior Light, Exterior Fan, 12VDC Neg)

Pins 1 & 5 not used

If either thermal fuse is blown/tripped NO DC for Gas Valve
*thermal fuses only affect Gas Valve DC unlike many other Dometic Models were ALL DC is lost

So Voltmeter
Fridge Controls on LP Manually the check voltages:
Pin #6 to Pin #7 (DC+/DC-) DC Supply
Pin #2 to Pin #7 (DC+/DC-) DC to thermal fuse/stack fuse
Pin #3 to Pin #7 (DC+/DC-) DC from stack fuse
Pin #4 to Pin #8 (DC+/DC-) DC to/from Gas Valve Solenoid

Suspect Thermal fuse/stack switch
*Stack switch is resettable
Otherwise circuit board-----OUCH!

[gilly2022]

Thanks Old Biscuit.. It's late right now but I'll give it a shot tomorrow. Much appreciated for the reply. I'll have to look up the schematics of the board (pins) so it may take me a while..lol. But we're camping ..so lots of retired time... cheers

[Old-Biscuit]

J1 Center of board

Top Row Pins 1 thru 4
Bottom Row Pins 5 thru 8

Pins are numbered left to right

[Fridge Defend]

Originally Posted by gilly2022

Hi all...gone camping and the fridge not working at all. The model is Dometic dmr702 and I've checked all fuses ( I think), power to the outlet, and tested some lines in the back of the fridge. I don't have any spark or gas. We have gas through the stove, water and furnace. I have the panel lights working and can change modes and can turn them off and on. No interior light though and I've turned the thermostat up to the highest. We haven't used the trailer for 2 years due to covid so it might be dirty but the trailer is a 2019 and only used it a few times and it was fine. I'm gobsmacked... tried everything I've seen on the internet to do next to buying a new circuit board ( $300 ugh! ). Any help would be greatly appreciated.. thanks so much.. gilly2022

The thermal switch is the most common cause of problem for this model of fridge. We have a photo of it on our site, also the part is:

CANTHERM Thermal Cut-Off Part Number DF152S.

This switch measures the air temperature by the burner of the fridge.

Hope this helps

[gilly2022]

thanks all..
watched a video (

https://www.youtube.com/watch?v=HvO0RzfxhzI

)
and he thoroughly explained on how to track the DC and 120v power all the way to the circuit board. I checked all the fuses along the way and on the board.
Soooo... from what I see is that the issue is in the board. I'm not giving up though ( in purchasing another circuit board quite yet). I'll try to keep you posted because .. God only knows.. I'll have to talk about this to someone. My wife is sick of hearing about it..... she just wants it fixed. I don't blame her..
Till later.. cheers Ross
ps. thanks again from other rv'ers..

[Old-Biscuit]

Well you can watch videos on Circuit Boards that are NOT for your fridge or you can check the DC on the J1 Pins paying attention to the Thermal fuse circuit and find if you have a blown thermal fuse or a bad circuit board