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I have a Siemens Dishwasher, model no SN26M890GB manufacture date 03 11 2009.
Its worked fine since new and then this week suddenly it has stopped working. It is completely dead and shows no sign. of life. There is nothing on the display. It has not been subjected to any movement / rough treatment or indeed anything unusual. One day it worked, next day it didn’t.
I checked the plug and house fuses and confirmed power is getting into the machine. Next I took the door apart to access the control panel from behind. dismantled and bench tested the main power switch, it is fine. I also refitted it and tested that power was getting to and from it through the yellow wire and no issue found.
I could not see or find any sort of internal fuse. I have seen a video where perhaps an older model had a fuse which can fail but i found nothing that looks like a fuse.
Next up, I checked the door latch. I dissembled and checked everything. mechanical operation of the moving bits on the body seem fine. Unfortunately it has a hall sensor and I do not know how to check these. obviously I tried activating it by placing the magnet part by hand into the receiving sensor and that did not produce any reaction. I also checked and found that the hall sensor was receiving power … about 5 or 6v if I remember correctly. I see that inside the plastic sensor body is a tiny circuit board which I was able to carefully extract and test under power directly against the magnet. Still no reaction from.
Any advice on what to check next would be gratefully appreciated. In particular is it possible to check the hall sensor , other than by putting a magnet on it. Do they fail? Its just a circuit board and I assume such things rarely fail. Should I just buy another one and see what happens ( they are only 20 quid )
I note that the hall sensor is the same as many other dishwashers including Bosch and Neff.
I have also pulled out the control panel circuit board and inspected it. There is no sign of any burning and no burning smells. Checking components on the circuit board is way beyond my skill level.
Yes, its getting power. There is a multi connector on which attaches to the right in the photo above. It has 6 yellow wires coming in and all 6 have about 4v on my multi meter. Curiously its the same no matter what I do with the main on off switch. Its 4v on each of the 6 connections whether its on or off. There is also a connection point with 3 contacts top right in the photo. It has no plug attached to it on mine (diagnostic access point ? ) and all 3 contacts have around 4v going to them, again regardless of where the main on off switch is
I just tested with my multi meter putting the black lead on the Dishwasher chassis and probed the contact points with the red live probe. I guess I am doing it wrong. Hows should I test it?
you cant assume there is an earth return
measure from pin to pin and make a chart of the voltages you get
Dave
I’m a bit confused with this. The only way I get a voltage reading from the control panel is if I have my black lead on the dishwasher chassis. If I simply attach both the black and red probes to any 2 contacts on the control panel I get zero volts. If I attach black to the chassis and red to any contact I am currently getting 3.5v
My knowledge of electrics is very basic but I understand a simple circuit. For most things to work they need an earth or neutral and then a live to form the circuit. On the control panel I can’t see how its getting its earth or neutral. Its plastic with no grounding and the 6 wires coming in are all live. Is that why my machine is dead ?
think your problem is with the main board
you can get 4v to earth even if the board power supply is dead
take out the main board and check that for damage
Dave
I’ve had it out and there was no sign of anything obvious. There is nothing black or burnt. If its the mainboard its probably not worth fixing. Time for a new one 🙁
yes it starts to get complicated from here. There is a power supply on the board but you would have to know how to find it and test it
Dave
Thanks for your help, as its 12 years old I shall buy a new dishwasher, its not worth paying for either a professional diagnosis or a new control board. I should have bought a Miele, they seem to last longer. 🙂
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