Leibherr F/F neither work

[Johnnyx]

New to all this as my F/F just packed up and has defrosted everything! Light comes on inside, so powers ok but no matter what setting you put the temp control on the compressor does not turn on.

Any ideas of where to start looking??? I am an electronics engineer so some diagnostic checks could be carried out easily but havn't got a clue about refridgeration and how it works.

Thanks in advance.

[nike123]

Is it with 1 or 2 compressor?

[Johnnyx]

Is it with 1 or 2 compressor?

It has one compressor.

[nike123]

Now, when we sorted that, we could start troubleshoot.
This is electrical problem, and we need to go upstream from compressor. First, you need to establish that compressor have voltage on his terminals. You have multimeter? Measure voltage at terminals of cable who goes toward compressor. It usualy have 3 wires (brown, blue, green-yellow) measure between blue and brown (black)
Be careful, this voltage kills! If you are not self confident, abort!

[Johnnyx]

Now, when we sorted that, we could start troubleshoot.
This is electrical problem, and we need to go upstream from compressor. First, you need to establish that compressor have voltage on his terminals. You have multimeter? Measure voltage at terminals of cable who goes toward compressor. It usualy have 3 wires (brown, blue, green-yellow) measure between blue and brown (black)
Be careful, this voltage kills! If you are not self confident, abort!

No problem can do that but not until I get home from work. I take it the compressor power is controlled from the temp controller (thermistor) inside the fridge via a relay. If so is the relay inside the fridge somewhere or is this an integral part of the compressor assembly?

If you could give some idea of how the circuit/system works that would be a huge help.

Many thanks so far.

[nike123]

Basically, circuit is composed of following parts and electricity goes in that order:
1. power source,
2. thermostat (could be electronical or electromehanical)
3. compressor starting device
4. compressor

What specifically is in your case I don't know, since you didn't gave model no.
Thermostat measure temp. and if it is higher then set temperature - differential, and if it is not defrost timer (or manual defrost) active (if have defrost control), his contacts are closed, and live from power source is forwarded to compressor starting device. Then live is applied to both main and start windings of compressor till compressor overcome starting reaction of refrigerant circuit. Then starting device stop supply live to starting winding. That is common for all refrigerators.

When you have 1 compressor fridge/freezer there is no control of freezer temperature. It is "controlled" by design!

[Johnnyx]

Thanks, at least that gives me a starting point.

Looking at the pictures and descriptions on the internet fairly sure model is CUPES4653 and is approx 5 years old.

As you say there is no control for the freezer only the fridge which is correct. I removed the interior light switch assembly this morning before coming to work and this appears to have the temp control, boost switch and what I assume is the thermistor/temp sensing device which is connected via a steel tube, similar to a thermocouple, and goes into the bowls of the fridge. I assume this goes to the switching device for the compressor.

Do you know if this unit has anymore electronics in it or basically what I have described to you here?

[nike123]

Thanks, at least that gives me a starting point.

Looking at the pictures and descriptions on the internet fairly sure model is CUPES4653 and is approx 5 years old.

As you say there is no control for the freezer only the fridge which is correct. I removed the interior light switch assembly this morning before coming to work and this appears to have the temp control, boost switch and what I assume is the thermistor/temp sensing device which is connected via a steel tube, similar to a thermocouple, and goes into the bowls of the fridge. I assume this goes to the switching device for the compressor.

Do you know if this unit has anymore electronics in it or basically what I have described to you here?

Do you have temperature display?

[Johnnyx]

No, just the rotating dial inside, 0-7 and a small switch with something like "COLD DRAWER" on it.

It has no electronic display for the fridge or freezer.

[nike123]

No, just the rotating dial inside, 0-7 and a small switch with something like "COLD DRAWER" on it.

It has no electronic display for the fridge or freezer.

Then you gave wrong model no.
Never mind, from what you said that is electromechanical thermostat, and there is no need for other electronic there.
Something like this:
http://tinyurl.com/2jhp8k

[Johnnyx]

Will post the exact model no. later and tell you how I got on. Thanks again.

[Johnnyx]

Will post the exact model no. later and tell you how I got on. Thanks again.

Right here goes! The model no is KSDVes4642-24.

I have tested the mechanical part connected to the temp dial inside the fridge and this appears to work OK.

The compressor and bits. I took the cover off the switching assy on the side of the compressor and removed all the connections and unplugged the switch/Relay. Had a good luck over it but couldn't see anything obviously wrong. Connected it all back up........................And now it works again!

This is both good and bad as ok the fridge works again.................but why and for how long. I have taken a few voltage reading while it is working so this may help if it goes wrong again.

Thanks for your input and you may hear from me sooner rather than later!!!!

[Electrocoolman]

Hi JohnnyX,
When you removed the start relay from the compressor, was a coil of enamelled wire visible? or was it an enclosed plastic 'lump'?
The first type could be what you've got as they are electro-mechanical and disturbing it could be the reason why your compressor is now running.
The second type is a 'PTC' and works on a thermal semiconductor action, and usually fails big time.

I think you would be wise to source a replacement, as sooner or later the same thing will happen again...just after restocking the freezer!

You will need to quote the compressor make and model from the label on the side of the compressor inorder to make sure you get the correct relay.

[Johnnyx]

Hi JohnnyX,
When you removed the start relay from the compressor, was a coil of enamelled wire visible? or was it an enclosed plastic 'lump'?
The first type could be what you've got as they are electro-mechanical and disturbing it could be the reason why your compressor is now running.
The second type is a 'PTC' and works on a thermal semiconductor action, and usually fails big time.

I think you would be wise to source a replacement, as sooner or later the same thing will happen again...just after restocking the freezer!

You will need to quote the compressor make and model from the label on the side of the compressor inorder to make sure you get the correct relay.

Well it did fail again. Got up this morning and OFF again. Need to check if the start relay energising voltage is present from the temp controller so I can tell which is at fault, temp controller or start relay.
At least the compressor seems OK.

Any idea where is the best/reasonable place to source spares from ???

Cheers John.

[Electrocoolman]

Johnnyx,
If compressor is receiving power, but not starting it will draw a heavy current and cut out on either the external or internal overload....it means that the compressor will be hot (or at least warm) to the touch.
If cold, it is not receiving power...so look at the control pcb or thermostat.

The start relay (if not the PTC type) will be a CURRENT relay....at startup, the stationary motor will draw a large current, which pulls the relay in, which connects the start winding into circuit.

What is the compressor MAKE and TYPE. We will then be able to guide you some more, but you should be able to test to see if the compressor has power to it.

[Johnnyx]

Johnnyx,
If compressor is receiving power, but not starting it will draw a heavy current and cut out on either the external or internal overload....it means that the compressor will be hot (or at least warm) to the touch.
If cold, it is not receiving power...so look at the control pcb or thermostat.

The start relay (if not the PTC type) will be a CURRENT relay....at startup, the stationary motor will draw a large current, which pulls the relay in, which connects the start winding into circuit.

What is the compressor MAKE and TYPE. We will then be able to guide you some more, but you should be able to test to see if the compressor has power to it.

Looks like the thermostat is knackered, have ordered a new one, just waiting for it to arrive.