Thetford fridge not working

[Mel]

On site on EHU. Everything else that works on EHU working. Fridge fine when arrived a few hours ago. Then electronic display flickering. Turned off master. Tried to turn off fridge. Having none of it. Unplugged ( not trying to run it on gas) still flickering. Removed fridge fuse. Still flickering Removed fridge ignition fuse. Fridge display stopped flickering. Fuse not obviously blown but will get a new one tomorrow.
Any other suggestions?
Please note two things. Any answer involving the word Multimeter is of no use to me.
Second, as the Prosecco is rapidly warming I have taken it upon myself to drink it.
Thanks in advance
Mel

 

[RogerL]

Running it on gas seems the obvious solution - do you have a reason for not doing so?

 

[Mel]

Running it on gas seems the obvious solution - do you have a reason for not doing so?

Can’t change the display to select gas. The display is just flickering and none of the buttons, to change source or turn off entirely are having any effect. Also should say that having removed the fridge ignition fuse the whole fridge display has gone off.
Thanks though
Mel

 

[Hutch]

Sorry Mel, sounds like a new PCB repair board, had one about 2 years ago. £170 ish. Keep the Prosseco outside until needed.

 

[Mel]

Sorry Mel, sounds like a new PCB repair board, had one about 2 years ago. £170 ish. Keep the Prosseco outside until needed.

Drat and double Drat. Prosecco needed now. Fear not, Prosecco won’t have a chance to warm up. 😉
Mel

 

[Buckman]

Sorry Mel, sounds like a new PCB repair board, had one about 2 years ago. £170 ish. Keep the Prosseco outside until needed.

Having had the same issue with a Thetford fridge I would agree. Apparently the PCB gets condensation on it and the tracks rust away.
There is a company that refurbishes them for a fraction of the original price, but I cannot remember the name and sadly for some reason I never bookmarked the site.

 

[Mel]

Thank you both. I will have a word with the caravan engineer that does our servicing.
Mel

 

[Mel]

Quick update. Just replaced the fridge (15A) and fridge ignition (5A) blade fuses. More in hope than expectation. Fridge came on! We will see if continues to work. 🤞
Mel

 

[Anseo]

Quick update. Just replaced the fridge (15A) and fridge ignition (5A) blade fuses. More in hope than expectation. Fridge came on! We will see if continues to work. 🤞
Mel

Nice one Mel, and you said you weren't handy on the Destroy it Yourself front.

I'm impressed, well done

 

[Dustydog]

Excellent! We’re the two fuses blown?
Do you have any Electrical Contact spray? Squirt it on the fuse holder contacts.

 

[Mel]

Excellent! We’re the two fuses blown?
Do you have any Electrical Contact spray? Squirt it on the fuse holder contacts.

Fuses not obviously blown. Still wondering if the PCB is on its way out and it has just had chance to dry out while we have been using the van. Only time will tell. In the meantime I have cold Prosecco. Happy Bunny icon.
Mel

 

[bertieboy1]

Fuses not obviously blown. Still wondering if the PCB is on its way out and it has just had chance to dry out while we have been using the van. Only time will tell. In the meantime I have cold Prosecco. Happy Bunny icon.
Mel

Hi,
Sometimes a microprocessor driven system sometimes gets into an everending loop because it doesn't know what to do.Switching off the power supply usually resets the microprocessor and it works ok after powering it up (you may have noticed this with a computer).Maybe this is what happened to you.
This happened to our microwave oven at home,we pulled out the plug for 30 seconds and it worked OK after putting plug back in and switching on

 

[Mel]

Thank you. When it first started flickering, we did turn it off by switching off the master and unplugging EHU. Turning it back on didn’t work. We then removed the fuses. It was 2 days later that we replaced the fuses, but also turned off the master and unplugged the ehu again in order to it. So you may well be right and it needed a longer period switched off than we gave it the first time. Time will tell I guess.
mel

 

[RogerL]

Hi,
Sometimes a microprocessor driven system sometimes gets into an everending loop because it doesn't know what to do.Switching off the power supply usually resets the microprocessor and it works ok after powering it up (you may have noticed this with a computer).Maybe this is what happened to you.
This happened to our microwave oven at home,we pulled out the plug for 30 seconds and it worked OK after putting plug back in and switching on

That's a fairly well-known first step for electrical devices going right back to the valve era, ie well before micro-processors - as well as switching off, remove the plug from the socket - but your point is a timely reminder that it may easily cure the issue, at worst it takes just a minute or so

 

[Baron Von Greenback]

That's a fairly well-known first step for electrical devices going right back to the valve era, ie well before micro-processors - as well as switching off, remove the plug from the socket - but your point is a timely reminder that it may easily cure the issue, at worst it takes just a minute or so

its to do with switches and relays becoming stuck - the ferranti reset as the professionals know it is recognised procedure and should not be taken lightly

 

[bertieboy1]

its to do with switches and relays becoming stuck - the ferranti reset as the professionals know it is recognised procedure and should not be taken lightly

It's nothing to do with stuck switches and relays that's something else completeley,no reason why it should not be taken lightly

 

[JTQ]

The fridge controls are 12 Volt powered by the battery, nothing directly to do with the EHU that provides mains.
Your "cure" seems to suggest it "could" even have been no more that from a poorly connected fuse, oxidation of the plating or similar making very poor contact till replaced.

 

[Mel]

Hoping you are right JTQ. So far there seem to be 3 possibilities:
1. The fuses
2. Removing the fuses for 2 days bfore replacing them, effectively removed the fridge from power and did a reset
3. Being in the van with ventilation and heating dried out a dodgy PCB.

There may be other possibilities
We will see what happens
Mel

 

[Buckman]

Hoping you are right JTQ. So far there seem to be 3 possibilities:
1. The fuses
2. Removing the fuses for 2 days bfore replacing them, effectively removed the fridge from power and did a reset
3. Being in the van with ventilation and heating dried out a dodgy PCB.

There may be other possibilities
We will see what happens
Mel

What happens sometimes is that the metal on the fuse or fuse holder corrodes ever so slightly and the resistance increases dropping the power. By removing the fuses and replacing them there is the possibility that you break that film or scrape them cleaner and the appliance starts to work again. Just another possibility.

 

[bertieboy1]

What happens sometimes is that the metal on the fuse or fuse holder corrodes ever so slightly and the resistance increases dropping the power. By removing the fuses and replacing them there is the possibility that you break that film or scrape them cleaner and the appliance starts to work again. Just another possibility.

Hoping you are right JTQ. So far there seem to be 3 possibilities:
1. The fuses
2. Removing the fuses for 2 days bfore replacing them, effectively removed the fridge from power and did a reset
3. Being in the van with ventilation and heating dried out a dodgy PCB.

There may be other possibilities
We will see what happens
Mel

2. 2 days is rather excessive,30 seconds is more appropriate
3, You mean a pcb with dry solder joints ?

 

[Mel]

2. 2 days is rather excessive,30 seconds is more appropriate
3, You mean a pcb with dry solder joints ?

It was 2 days because that is how long it took before I went to a blade fuse supplier.
No idea what sort of PCB. TBH I don’t even know what PCB stands for( or for that matter what a dry solder joint might be).
My skills start and end at replacing the fuses.
sorry
Mel

 

[Hutch]

The PCB, is Printed Circuit Board, for my fridge it was a repair kit which was the PCB and box for the rear of the fridge and also a new electronic facia control panel.

 

[otherclive]

It was 2 days because that is how long it took before I went to a blade fuse supplier.
No idea what sort of PCB. TBH I don’t even know what PCB stands for( or for that matter what a dry solder joint might be).
My skills start and end at replacing the fuses.
sorry
Mel

And opening the Prosecco, albeit a tad warm. 🍾