Dometic Rmd 8505 F/f

[Terry]

Before we payout over £225 for a new control PCB I was wondering if anyone had had a similar problem and found a different solution
FF was working good about 2 mths ago. Come this morning turned it on and nothing. When the on button is pressed the light comes on inside the fridge but off as soon as you let it go. Then after trying a few times it sprang into life for a few seconds then off several attempts later we found it would spring into life for anything fr 5/10 secs to a couple of mins before stopping again. It did this on both gas and leccy.Did not try on 12v engine running. It did seem to work better on gas.
We have both 240v and 12v to the back of FF.
While checking the FF fuse on the Rapido CBE distribution module I noticed a green flashing light ( with in the unit) which flashed 5 times followed by 2or3 then 1 I have no idea what this was for or even if it's anything to do with FF but cannot find any info on it. Any help would be great

 

[Terry]

Lenny HB does this sound like a PCB problem or possibly wiring? The fact that it stays on a while then goes off has got me confused

 

[Lisa]

Took a little vid of it.

 

[Steve and Denise]

Ours had a similar thing happen it was condensation on the pc under that plastic cover causing beeping removed it dried it with a hair dryer then refitted it I think I bought a spare just in case oh and sprayed it with pc lacour

 

[Jimbohorlicks]

https://www.motorhomeowners.org/post/dometic-fridgefreezer-on-the-blink-6832745
Hi Terry,similar issue on the above link ,if you read thru the thread ,it seems it cleared itself after a few days switching it on and off,don't know if it will work with yours.
May be a dry joint or loose connection.

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[Jimbohorlicks]

If you are looking to try a new front control panel have you checked with your local caravan breakers,thought you had a few contacts there.

 

[Terry]

I had loads of contacts back on Yorkshire unfortunately it's 2 hours drive away from this place. Anything you want done here nobody wants to do it or they want a week's wage for a day's work

 

[Steve and Denise]

I had loads of contacts back on Yorkshire unfortunately it's 2 hours drive away from this place. Anything you want done here nobody wants to do it or they want a week's wage for a day's work

That’s what happens when you move to upperclass areas

 

[Terry]

That’s what happens when you move to upperclass areas

I would like to like that but back in Yorkshire I knew everybody and we all did favours
I will try the HD on the panel nothing to loose thanks Steve

 

[Lisa]

Thanks Steve and Denise and Jimbohorlicks for your replies.

Bit disheartened, to tell the truth. Terry has always put himself out to help others and when the shoe is on the other foot?
Oh well....live and learn.

Anyway, for some reason it all works today. Long may it last!

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[Steve and Denise]

Thanks Steve and Denise and Jimbohorlicks for your replies.

Bit disheartened, to tell the truth. Terry has always put himself out to help others and when the shoe is on the other foot?
Oh well....live and learn.

Anyway, for some reason it all works today. Long may it last!

Worst case is we have a big compressor cool box so you won’t be stuck

 

[Lisa]

Worst case is we have a big compressor cool box so you won’t be stuck

Cheers Steve, you’re a ️

 

[GeoffnDee]

If the problem comes back the information regarding the light/catch fault ,and what can be done about it ,can be found if you google , Dometic Refrigerator bulletin R84-A , (myrvworks.com PDF).

 

[Jimbohorlicks]

Thanks Steve and Denise and Jimbohorlicks for your replies.

Bit disheartened, to tell the truth. Terry has always put himself out to help others and when the shoe is on the other foot?
Oh well....live and learn.

Anyway, for some reason it all works today. Long may it last!

Well that's good news anyway.Sounds like a dry joint or loose connection. Its probably those bumpy roads around your way.
In defence of others I think fridge electrical PCB parts are not easy things to sort out.

 

[Lenny HB]

Lenny HB does this sound like a PCB problem or possibly wiring? The fact that it stays on a while then goes off has got me confused

Not seen that fault before, the light is fed from the control panel so looks like something to do with the panel. Our Hymer has a separate 2 amp fuse that feeds the control panel from a permanent live. Worth taking the fuse out and leaving for a bit to see if the panel resets when it reboots. If you can't find the fuse you could disconnect the leisure battery.

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[Antique]

Took a little vid of it.

Yep, got the same flashy light thing then it's off for good (but fridge still cools)
BUT..
Only when on ehu.
Also techtower gas oven won't work when on ehu.

On 12v and gas only - all is fine.
Wierd !!

All the best

Antique

 

[Terry]

If the problem comes back the information regarding the light/catch fault ,and what can be done about it ,can be found if you google , Dometic Refrigerator bulletin R84-A , (myrvworks.com PDF).

Thanks but it's not a light catch fault, read op.

 

[Terry]

Not seen that fault before, the light is fed from the control panel so looks like something to do with the panel. Our Hymer has a separate 2 amp fuse that feeds the control panel from a permanent live. Worth taking the fuse out and leaving for a bit to see if the panel resets when it reboots. If you can't find the fuse you could disconnect the leisure battery.

Hi Lenny, it's decided to work now. I tested and shook every wire I could, removed the panel a couple of times to check that then Lisa removed it a couple more times still no joyIt was left for a good hour a couple of times between checking etc so I think that would be long enough to reset.We left it with no voltage etc overnight. Then this morning went out to try what Steve suggest hair dryerLisa suggested to try it all again before HD and it sprang into life so we don't know if it was the threat of HD or overnight reset.
Thanks also to Drexxer for his pm
I managed to get hold of my mate Paul who told me if all else fails he would look at the circuit board for us Unfortunately this entails a two hour drive each way

 

[WillandLes]

Before we payout over £225 for a new control PCB I was wondering if anyone had had a similar problem and found a different solution
FF was working good about 2 mths ago. Come this morning turned it on and nothing. When the on button is pressed the light comes on inside the fridge but off as soon as you let it go. Then after trying a few times it sprang into life for a few seconds then off several attempts later we found it would spring into life for anything fr 5/10 secs to a couple of mins before stopping again. It did this on both gas and leccy.Did not try on 12v engine running. It did seem to work better on gas.
We have both 240v and 12v to the back of FF.
While checking the FF fuse on the Rapido CBE distribution module I noticed a green flashing light ( with in the unit) which flashed 5 times followed by 2or3 then 1 I have no idea what this was for or even if it's anything to do with FF but cannot find any info on it. Any help would be great

We have a very similar problem with an RMD 8505 fridge. Three weeks ago we found that the fridge after running on mains at home would not switch to battery when setting off and would not switch to gas when we arrived at a festival. Since then I have been trying to diagnose the problem. It comes on for a few seconds avfter turning off the 12v supply for a while but then turns off and remains dead. I have confirmed that I have 12v and 240v at the external control block PCB so the onboard fuses are ok. I have tried replacing the PCB for £150 but that did not help and returns are not accepted.
I then ordered a new display control panel for £289 from Interspares. That was 10 days ago and they now tell me that they have a few on order from their suppliers who are trying to get them from Germany. The current delivery period is about 4 weeks so some time to wait yet. We are going to Europe soon so may have to travel without a fridge but have bought a cooler box to cover us in the interim.
I have wondered if there is a fuse somewhere at the back of the fridge but cannot find an exploded diagram or circuit diagram anywhere online to check that. I can't believe that it could be a thermocouple or thermostat but not totally sure.
I have contacted various motorhome service workshops and mobile engineers in the Buck/Berks area but nobody has the availability to look at it for weeks and maybe months.
Be prepared for a long wait without your fridge!!

 

[Terry]

It's decided to work nowI tested everything just like you. The only thing I could not test was the ribbon wires from back of FF to the front control panel.
All good information for anyone else suffering with the problem

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[WillandLes]

We finally received the control panel from Dometic after a 2-month wait. Success though, we now have a working fridge. It seems that the control panel is the most likely cause of the problem in the Dometic fridge. For us, it was a burnt-out chip.

 

[Les]

Before we payout over £225 for a new control PCB I was wondering if anyone had had a similar problem and found a different solution
FF was working good about 2 mths ago. Come this morning turned it on and nothing. When the on button is pressed the light comes on inside the fridge but off as soon as you let it go. Then after trying a few times it sprang into life for a few seconds then off several attempts later we found it would spring into life for anything fr 5/10 secs to a couple of mins before stopping again. It did this on both gas and leccy.Did not try on 12v engine running. It did seem to work better on gas.
We have both 240v and 12v to the back of FF.
While checking the FF fuse on the Rapido CBE distribution module I noticed a green flashing light ( with in the unit) which flashed 5 times followed by 2or3 then 1 I have no idea what this was for or even if it's anything to do with FF but cannot find any info on it. Any help would be great

Terry had same problem lots things could be dealers just keep changing boards. Eventually bought new front board of Amazon France £159 worked but fridge has its moment.Also the board can get condensation in it and you can take it out and try dry it out but it’s a lottery ( fridge is a pile of poo) good luck