Bosch SMS68MO2GB/D4 No Power

[Chiefcelt]

Hi. Be grateful if anyone can help. 84yr old mums machine stopped after last use. NO Power to Led Door Panel. The 10 Amp fuse had blown in Plug. I’ve stripped machine down and wondered if a Faulty Heat Pump would cause this to happen and also as a result stop the power going to Led Door panel somehow?? I’ve a photo of where power connector attaches to Pump 12014980 (0450 bosch diagram). Forum wouldnt take File size of photo!
Hope thats enough info.
Many thanks
Alan

[electrofix]

to post photo
host on another site and post a public link

when you found the fuse had gone did you replace it and see if it came on or came on here to ask ?

Dave

[Chiefcelt]

Hi Dave. Replaced witha 13 amp fuse as i didnt have a 10Amp handy. It didnt come on. Was dead still. Friend Did a continuity test on the fuse to check it was blown.
Cant think where to post and link a photo at thus very moment. Been trying to unclip the Heatpump hose clip which has the undo clip at back of the bloomin pipe outlet.

[electrofix]

Chiefcelt wrote:Hi Dave. Replaced witha 13 amp fuse as i didnt have a 10Amp handy. It didnt come on. Was dead still. Friend Did a continuity test on the fuse to check it was blown.
Cant think where to post and link a photo at thus very moment. Been trying to unclip the Heatpump hose clip which has the undo clip at back of the bloomin pipe outlet.

forget that leave heat pump alone

you could unplug the heater which is the large plug with 3 wires on the motor but it wont stop display lighting up so i think your problem is more serious

rear right where the mains plug goes in is the main pcb remove the pcb and open it and look for damage

Dave

[Chiefcelt]

Hi Dave,
i did open up the Circuit board as i had to remove it to see the pump. Couldnt see any sign of burn outs on the PCB. Im no sparky though. Got me stumped at the minute.
one thing i forgot to mention earlier was that there was some water sitting in bottom of dishwasher after last usage. I put it down to the Filter having a fair build up of grease on it.

[electrofix]

sitting water wont affect it

you may have 2 faults here but cant be certain

the main pcb has the low voltage power supply built in to supply the electronics, normally 12v. if this fails it wont light up. To protect this circuit Boach fit a small resistor between 50 and 100 ohms. If this has blown then it will be totally dead. The bad news is i cant see it blowing a 10A fuse so there is likely another reason for that
from here on in it get technical, so it depends on your skill level how far we can go

Dave

[Chiefcelt]

Is it possible the heat pump has blown the 10 amp plug fuse and the resistor has gone too? I can follow what your saying logically but my skill set stops once i pass rewiring plugs or running in cables! Shame as i can fix most things.

Its a shame for Mum as the machine is only just 4 yrs old this week. Pretty poor given the cost. Maybe i could try a begging call To Bosch tomorrow!
Very frustrating. I should’ve gone to electronics courses! ‍♂️ Thanks for your responses Dave. Very grateful. Trouble with Dishwashers (as you know) , one needs to pinpoint issue or the repair can become uneconimical very quickly.

[electrofix]

Chiefcelt wrote: Trouble with Dishwashers (as you know) , one needs to pinpoint issue or the repair can become uneconimical very quickly.

so true and its the same for all appliances

As for the board if you call most enginneers out they would just fit a new board. Not many people go down to component level

Dave

[Chiefcelt]

Afternoon Dave, I managed to take the Heat Pump Jubilee Clip off after quite a struggle to access. The Heat Pump has a clear scorch mark on and around the centre pin. So…id say thats blown the 10amp fuse. I’ve ordered a New Bosch machine…now that i can take it Apart! I wouldve changed the Heat Pump but as you mentioned …The Resistor that protects the Door Lcd Screen may be gone too. I’d guess I’ve taken the right choice.
Anyway, thought i’d give you the feedback for your knowledge base. Thanks again for the input.
Atb,
Alan

[Chiefcelt]

Further Info on this Bosch Machine Issue. I also removed the PCB entirely to check the board overall. There was a scorched circuit and leading to two thingies! Resistors perhaps.
They did have Numbers 181 and Something .77
The red live wires (live or live and neutral?) both fed from the Heatpump connectors to the PCB and the same connections on PCB board were scorched, both obviously then led to the resistors or whatever they are. The light grey wires on the plastic connectors on the pump led to the PCB also. I seem to recall that thinner yellow wires led up from the PCB to the LCD area on the top of the door.
this may help folks know where to look. 🙂
i suspect there is an inherent weakness in this Bosch machine design. One would think that ine wouldn’t have to Buy a new machine after 4 years or indeed spend £220 on two Major Parts….not including the £99 Call Out charge.
Anyway, I hope this Info will help someone save the many many hours of time I used up investigating. Shame I couldn’t post the images of damge which are very clear.
Atb,
Alan.

[electrofix]

having both parts fail at one is not common but not unheard of. most of the time its just the pump. The heater is so flimsy its a regular fail.

the other problem is the fact the cheaper ones use a plastic lower tub. getting leaks between the plastic and steel joint is common

Dave

[Author]

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