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No doubt you are all familiar with Servis machines that are totally dead apart from the door locking. You change the module and the fault is cured. The modules never seem to show any visible damage so it must be down to component failure but which component? If there is a certain component that regularly fails I would like to have a go at fixing them myself. I’ve sometimes changed short circuited triacs on Hotpoint machines but I’m a bit out of my depth with these Servis ones.
Re: Servis Modules
Used to be a very common failure but dont get so many anymore, sadly as the newer modules are differrent.
Its usually the 2 large, white ceramic power resistors that you can see sticking up in paralell with each other. If one goes you often loose spin or when both go you get the problem you described. They are an unusual value, at 6.2K but they can be replaced with either 6.8k or 5.6. I have used both without problem but use the 6.8 to err on the side of safety. Connect sell them.Re: Servis Modules
What ever you do do not send them to QER if it is any thing more than a simple repair as they cannot repair them. Also they have a girl/woman working for them who will tell you that if there is not motor action to tighten the belt! I do not know how that will help!
Bill Ellis
Re: Servis Modules
Thanks. I suppose the resistors are used to reduce the mains voltage rather than fitting a transformer. I will start checking them. :tup:
Right, this is really annoying me.
I know why the belt tension matters as it somehow measures for OOB detection IIRC but I simply cannot remember why right now. That’s annoying me.
Anyone care to refresh my memory?
K.
Re: Servis Modules
Part of the load is sensed by back EMF (a la old Philips machines) – sloppy belt, poor drive, so motor doesn’t drive to the “profile” stored in the computer.
I think………
Chris.
Re: Servis Modules
The electronics are reacting to the current drawn by the motor ie no load(appreciably), no spin (on some DMPU and onwards). When the drum lifts a weight to the top of the appliance it requires more effort than the lowering of the weight, too much difference and out of balance kicks in.
The 1230 belt was a neoprene type that stretched and caused no spin, although it would wash. The replacement belt is now rubber and does not stretch so much. There was no tension adjusters to the motor points on these service appliances.
Whilst the modules are a problem a new belt does fix “no spin” quite often.
Kevin
Re: Servis Modules
Although my question was a general one I do have a current job on one of these machines, model M3510S. This has an enamel tub and there is adjustment for belt tension but the machine is not filling, draining or turning the drum. I checked the resistors in situ and they seem to be about the right resistance. I measured the voltage across them and it was about 180 volts in each case.
Re: Servis Modules
When I did Servis warranty work for GB we had all sorts of weird and wonderful faults.
The neoprene (pale colour) belts do stretch I had an MFI machine the week before christmas where the guy had been told it was the module by a local guy, I called changed the belt for a black one and away it went much to his astonishment .
On the Domar machine (Model no ends with an M) the edge connectors were a problem also had lots of 3022’s with 24 Volts to the pump sometimes module worked other times not when not suspect the harness.
Rule of thumb~ if the motor runs with no belt on then its normally belt tension.
If no no drum action full stop then its normally module but beware as the motors sometimes take out the modules look for a leak from the dispLawrence
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