Whirlpool fridge freezer, defrost timer location

[cahornsey]

I have a whirlpool Model ARC7720 fridge freezer, it's keeps turning itself off every ~10 hours and you have to reset it. I think the problem may be the defrost timer but I can not locate it. Any idea where it might be on this model or does it even have one? thank you

[TJW]

Whirlpool US doesn't seem to recognize it's UK counterpart. It is frost free.
It has  a defrost element, but I can't find a timer listed. There has to be one, under some other name. Look at what defrost thermostat: bimetal looks like. Strange loking to me, but a timer of some kind has to throw power to it.
http://www.4whirlpool.co.uk/cgi-bin/catalogue.pl?section=47873&m_page=5&path=47873

[Repair-man]

Or a board. He never mentioned if this was electronic controls or not.

[JWWebster]

You say you have to reset it each time. Explain how you reset it.

[cahornsey]

I 'reset' it by turning it off and back on again via the control panel at the back of the Fridge compartment. It then works for about 8 hours or so before turning itself off again.

The control panel has a small box behind it which contains a PCB manufactured by Ipotesi and labelled 'R20'. It has three wires coming out of it labelled 'CV1' (Brown wire), 'CV2' (Black wire) and 'CV3' (Blue Wire).

I believe that two of the wires run down the back of the machine to the compressor. I'm not certain what the third does.

I still can't find a defrost timer of sorts and I'm still uncertain how to go about identifying let alone rectifying the fault.

As ever, any assistance is much appreciated! If I can't get this sorted I won't be buying a whirlpool again, probably a Samsung!

[jumptrout51]

Samsung??? Please do not trade one problem for another.

[JWWebster]

Their is no defrost timer. A small amount of dc voltage is sent to a thermister. The main brain checks with the thermistor constantly. As the temp changes on the termister, the brain determins their may be a defrost cycle needed in the near future. So the brain also meaures how many times the door has been opened and closed. It uses the resistance from the thermister and the door counter to determine that the damn thang needs to be defrosted. If  you never open the door for several days the board will actually go into a vacation mode. Yours is on vacation  I would replace the dollar store el cheapo asz sensor/thermister first. Many folks would concur with me that have blown a lot of money on expensive boards. It could be something as simple as the thermistor is out of place and not able to do its job. Just guessing.