[mikevernon]

Re: Bosch fridge freezer not cooling but compressor runs

Thanks Gary. I’ve found QER via a Google search.

The next problem is locating and removing the control board. I’m assuming it is behind the control panel at the top of the fridge, but I can’t see how to remove it. The panel has only 2 buttons. The on/off button works but nothing at all happens when I press the temperature button. This seems to confirm that I have a control board problem but I’m still reluctant to gamble on buying a new one without further testing.

Can anybody help?

The control

[mikevernon]

Re: Bosch fridge freezer not cooling but compressor runs

I have now investigated further and discovered that the defrost heater is on all the time. If I unplug the thermal fuse the heater stops and the evaporator cools, but the evaporator fan still doesn’t run. Am I right in thinking that this indicates a control board fault?

If the control board is faulty, does anybody in the uk offer a repair service? A new Bosch part is prohibitively expensive.

[mikevernon]

Re: Hotpoint Mistral warm fridge / cold freezer

Yippppeeeee!!! Success!!!

The new thermistor arrived this morning and has cured the problem, BUT I was very confused at first because the new one had exactly the same resistance as the old one at room temperature. Warming them in my fingers produced a similar drop in resistance, so at that point I very nearly gave up and took the freezer to the local tip.

But as a last resort I put both the old and new thermistors into a working freezer for 5 minutes then re-measured their resistance. And this time there was a big difference. The new one showed a resistance of around 13 kohms, but the old one had actually fallen to around 1.5 kohms, showing that it was defective at lower temperatures.

I hope my experience will help somebody else on here.

[mikevernon]

Re: Hotpoint Mistral warm fridge / cold freezer

After trawling through lots of very similar problems posted on this forum I’ve reached 3 conclusions:-

1. I don’t properly understand how this F/Freezer works

2. The majority of people posting on here know as little as I do, and often less

3. The most likely cause of the problem is a faulty yellow thermistor

Having looked at the advice page on this website I had decided that both thermistors were ok because they both showed decreasing resistance as I warmed them in my fingers (testing simply involves unplugging the plastic connector blocks and inserting the multimeter leads into the two terminals). I ignored the fact that the yellow one showed less than half the resistance of the green one, at around 1.5kohms.

I was sidetracked by the fact that I couldn’t see the evaporator fan running (the one behind the back panel in the freezer compartment, not the one at the bottom next to the compressor). I read that it doesn’t operate until the freezer temp has fallen below -15 degrees, so I ran the freezer until it reached -20, but still no fan. This made me think the fan might be faulty, or maybe the control board, but I hate the idea of diagnosis by trial and error, replacing parts until the problem goes away.

I then decided that if the yellow thermistor switches the fan on and off, I should try disconnecting it. Sure enough, with the thermistor unplugged, the fan runs. So that has convinced me that the yellow thermistor is very likely to be the problem, and since they are available on ebay for £5.99, I’ll take the risk.

If that doesn’t fix it, does anybody want a free Hotpoint Mistral Plus in green?

[mikevernon]

Re: Hoover PE235 drum obstruction – how do I remove a paddle

Thanks again Martin. Out of curiosity, in what way does the support spigot fail? Is it worth stripping it down to see what has happened?

[mikevernon]

Re: Hoover PE235 drum obstruction – how do I remove a paddle

Hi Martin. Many thanks for your replies to both of my posts about this machine: much appreciated.
I’ve now managed to removed the door seal and the drum turns perfectly without it. No stiffness, noise or bearing play. But it is clear that the drum is out of true and that it was rubbing against the rubber seal during each rotation.

PS. I’ve just looked again and in fact the drum diameter is fairly consistent, but if I measure the gap between the rim of the metal inner drum and the rim of the plastic outer drum, it varies between approx. 7mm and 18mm at any given point as the drum is rotated. The only explanation I can think of is that the bearings have moved in their housing or that the shaft on which the drum rotates is bent. Am I correct and is there any remedy apart from a new drum assembly?

[mikevernon]

Re: Old Bosch machine – drum not turning – update / suppre

Update. The problem turned out to be the motor brushes – nice cheap fix.

Strangely, the machine worked for a couple of minutes with the new brushes then tripped the RCD. Further investigation shows that it trips the RCD even with the machine switched off. I’ve narrowed it down to the suppressor (mains filter) although it looks normal. So the next step is to either replace or bypass the suppressor, but I can’t help wondering why it should fail just after replacing the brushes. Is it just coincidence?

[mikevernon]

Re: Old Bosch machine – drum not turning

I will check the brushes, but what could be making the strange noise?

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

Hi nomadPaul, and thanks for your contribution.
I understand your point exactly, and the switch does indeed have a mechanical linkage to the door handle. However, this linkage physcally prevents the switch from being turned on when the door is open, and since I’m testing the switch off the machine I have made sure that the linkage is in the “door closed” position so that I can operate the switch, if that makes sense. So although that might have provided the explanation for pins 1 and 2 being inoperative, it still leaves me in the same position and I still think the switch is the likely culprit.
Thanks also to kwatt for the list of machines with the same on/off switch. That could be very useful.

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

…..I’ve looked at the wiring diagram and all 6 wires, all 6 connections have functions. The 2 that you are puzzled over most likely are the 2 that activate the relay on the main Control Module.

Thanks for looking, Martin. If those two wires activate the relay on module, then surely they should receive power when the on/off switch is turned on? They don’t, so surely that supports my supposition that the switch is faulty?

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

Hi Martin. I thought you were going to consult your wiring diagrams to find out the function of those two pins on the on/off switch. I still think that might be the cause of the problem.
I’ve always disliked the approach of just replacing parts in the hope that they might be the cause of the problem, rather than methodically testing components to identify a faulty one. That is why I’m reluctant to replace either the module or the switch unless I can be sure that they are faulty.
Regards
Mike

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

Thanks for your kind offer of help Martin. The full model number is SGS43A12GB/27. Sorry I got it wrong earlier.
It is a UK model dishwasher.
The 6 pin on/off switch seems to be common to a few different models.
I look forward to hearing from you.

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

Martin. Sorry, the model number starts with SGS, not SWS.
Perhaps I didn’t make my question clear enough. I wanted somebody to explain why there should be two pins on the switch which are not connected to any other pins and are not affected by operating the switch. If these two pins are redundant, as they appear to be, why do they have wires connecting them to the control module?
Does anybody have one of these 6 pin switches handy? If so I’d be really grateful if they could check to see if the two pins at one end are redundant. The part number on the switch is 5600.041.906

[mikevernon]

Re: Bosch dishwasher – faulty on/off switch?

Thanks for your reply Tim. If it is likely to be the module at fault then I’ll scrap the dishwasher, which is a shame because it is in lovely condition otherwise.
But I’m still not convinced about the on/off switch. There are two terminals which are not connected to the other four terminals, and are not affected in any way by the switch being on or off. These terminals are connected by white wires to the control module, so surely they must have some function? That suggests to me that there is a fault within the switch.

[mikevernon]

Re: Bosch SGS43A12GB has no power (no lights)

I now think the on/off switch may be the cause of the problem, which would seem a more logical explanation than the module. And cheaper!
I’ve tested the switch and the end two terminals appear to do nothing (there are 6 terminals and 6 wires connecting to them). Neither of these two terminals have continuity with any of the other terminals, whether the switch is in the off or on position. I can’t think of any explanation for this other than a faulty switch.
The switch terminals could just be corroded so I’m trying to pull the switch apart to have a look, but so far without success.
Has anybody managed to get the on/off switch apart?

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