Bosch WAE28368GB/56 No Motor Rotation

[PubGuy]

Problem :- No motor rotation, no error code.

Fault history:-

Machine left washing overnight, following morning full of water, no power to washer socket (breaker tripped).

Restore power, ERROR F16, clear error, start button gives two beeps no other response.

Motor brushes very worn and burnt - replaced, checked for other possible component or wiring faults- none found, replaced door interlock, still start button two beeps. 

Checked power module and found PCB track going to door interlock pin 2 vaporised  - replaced power module.

Current problem:- machine now fills and drains, presume it also heats water but not checked, no motor rotation of any kind and no error code.

Suspect from beginning that motor might have caused original problems, have tried to measure motor windings ETC but not sure what I should see.

Motor is Bosch Part No 00145678 with 7 pin connector.

Motor Readings:- Pins 1-2 25ohm, Pins 5-6-7 1ohm (any combination), Pins 3-4 no apparent reading, I might have pin numbers reversed.

Not tried to measure any motor voltages as its a bit difficult.

At the moment my money is on the motor.

Your thoughts will be most welcome.

 

 

[Whitegoodshelp (Andy)]

Hello PubGuy. Don't bother trying to measure voltages, it's potentially dangerous and not something engineers do anyway. We use continuity test meters with machine unplugged. Generally speaking you should get readings across the motor pins around the type you are getting. There's normally only 2 or 3 for the field coil, 2 for the carbon brushes across the armature and 2 that are very high resistance across the tacho coil. Depending on the type of meter used you may need to adjust the range to be able to get a reading from the tacho coil.

If the motor fuses the electrics it can always potentially damage something in the PCB. The problem you have is you don't know if the motor is still electrically OK or not without testing it with an insulation test meter (which uses 500 v DC). However, if there was a significant short to earth it should still trip the electrics.

Never discount the possibility something went wrong with the repair ie. poor connection in motor plug(s) after being disturbed, or brushes somehow not put in right. To test the motor take off the motor cover (if necessary) and test continuity down the 2 wires in the motor plug that connect to the carbon brushes. Then identify the wires that are left to work out which are the field coil and which are the tacho coil. The tacho coil wires are usually very thin. Test continuity across the field coil wires and the tacho coil wires. If you have continuity the motor should run. It may not run well, could even cough and splutter or even fuse the electrics but it should run. If you have continuity across all the wires but it doesn't run the chances are it's because of something else.

The door lock if faulty should stop everything working except maybe the control panel lights.

I have a lot of advice on this specific fault but it can only be fairly general Washing machine drum not turning

[PubGuy]

Hello Andy

Did some more digging the brushes go to pins 3 & 4 of the connector, Pin 4 has a thermal cutout (Klixon 15AM) in series with brush and is open circuit.

This cutout should auto reset so either excess current has blown it or it also has a none resettable failsafe.

Considering the other damage done originally repairing this motor would be too risky so it's a new one.

Thanks for your time.

 

 

[Whitegoodshelp (Andy)]

Thanks for the update. I can't say there can't be any resetting ones but all the TOCs inside motors I've seen are 1 shot. If they blow they are gone.