Hotpoint Mistral evaporator fan

[200dan]

Can anyone help? I have a Hotpoint Mistral Plus and am having problems with the operation of the evaporator fan. The freezer gets down to -22C, but the fridge remains warm due to evaporator fan not running. I've tested the fan, it seems to operate fine when 240V applied. The door switch is OK, as is the function of the yellow thermistor. I know that as the thermistor gets cold it's resistance increases, when this happens the fan does kick in and run for approximately 20-30 secs, it then cuts out and remains off. I am led to believe there is a fan cut out on the PCB (small blue blob!) could this be the problem? If so could I merely bypass it, i.e. short it out? Any help would be greatly appreciated.

[Brian_UK]

Hi Dan and welcome to the forum.

Can't give any direct help myself but have a look at UK White Goods forum here :-
http://www.ukwhitegoods.co.uk/module...hlight=mistral

It seems to be a thermister problem that is quite common.

[chillin out]

If the fan is cutting out on the pcb thermistor (blue blob), it is probably cutting out for a reason.

Remove the fan motor and have a good look at it, make sure there are no cracks in the plastic covering the windings. If it looks OK then, yes, bypass the thermistor. Crush it with a pair of pliers and then solder the legs together.

Chillin

[chillin out]

Also check the door switch, if the conacts are bad it might knock off the fan.

Chillin

[200dan]

OK now I'm a bit lost!

Rather than crush the blue blob, I desoldered it and replaced with a link. Result - Nothing. The entire unit was dead nothing functioned, no compressor no fans, not even the digital display! I then cut the link - still everything dead. So I replaced the little blue blob, and now everything works again - apart from the original evaporator fan cutting out as before. I must be at the wrong component! The blue blob I am dealing with is just alongside the large IC on the board. Surely, with the above results this can't be the fan cut-out thermistor can it?

[Brian_UK]

Sounds more like a small capacitor to me.

[chillin out]

Be carefull because there are a few 'blue blobs' on the pcb.
I think it's the one to the left, turn the pcb upside down and follow the track for the fan.

I seem to remember 3 resistors that look as if they were burnt, the fan connection is near there.

Chillin

[200dan]

Thanks for the advice, especially to chillin.

As suggested I traced fan supply to PCB and located correct thermistor. I desoldered it and replaced it with a link. Incidentally, a leg fell off the thermistor as I desoldered it which may have been why it tended to cut the fan out (due to excessive high resistance - dodgy connection). On replacing PCB I was faced with no compressor running. At first I thought I hadn't fixed it. Then I realised the unit had entered into defrost cycle! Once this was finished everything powered up and started running as it should including the evap fan (once the evap got down to temperature). Fridge and freezer both now appear to be working fine.

Once again many thanks for your help, I wouldn't have been able to do it without you!

Cheers
Dan

[Brian_UK]

Thanks for the update Dan, always glad to hear of a happy ending.

[deepheat]

hey there sorry to jump in here, i have the exact same fault as mentioned, could anyone point me in the direction of the pcb that has the offending component? many thanks.

[andyessex40]

Hi there - Can anyone point me to the location on the pcb of this problematic thermistor. I have the same problem.

Once I have located it does anyone know where I can find a replacement?

Cheers
Andy

[maisijane]

hi i replaced the thermistor. the fan came on for a few secs now off again any ideas what I do next?

[roche1800]

hi there, i am sorry i am unable to offer any technical assistance. i am looking for help myself! i have a Hotpoint Mistral approx 10years old, yesterday the fridge stopped working and saw it go to +21, whereas the freezer remained at -22 but the kids icecream had melted (think this was the heat from the fridge). tonight i heard a 'crack and pop' and it appeared to start cooling again, the only problem is that somewhere there is now a whirring (knocking sort of noise). having read some forums and some very useful tips i am now looking for some advice on which part to buy and what i need to take apart.

any help and advice would be greatly appreciated. cheers for now.