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Techdesk
Techdesk, Field Service Engineer
Category: UK Appliance
Satisfied Customers: 16407
Experience:  Whitegoods engineer working for a multibranded national company in the UK.
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Hi, I have a smeg oven (SE378MFX5) it worked fine, but Ive

Customer Question

Hi, I have a smeg oven (SE378MFX5) it worked fine, but I've just come back from a 4 week holiday and it no longer works - the only thing which has happened in between is my cleaner cleaned it!

It powers up and the clock and ventilation fan work, however:
a) non of the cooking elements work (top or bottom, even in grill mode)
b) the oven fan does not switch on
c) the amber thermostat light does not illuminate

However, I can hear the thermostat make a click sound when I turn it up from zero, so I’m guessing it’s trying to switch on the oven circuit but there’s no power getting through. My initial thought is there may be a separate fuse on the heating circuit which may (for whatever reason) have blown, but without a circuit diagram or stripping it down, i do not know if this is the case.

Any thoughts / help would be appreciated
Andi
Submitted: 7 years ago.
Category: UK Appliance
Expert:  Techdesk replied 7 years ago.

Hiya,

Is the clock set to automatic cooking?

As you haven't said that it's been set for manual, we'll start with the clock.

 

As nothing at all is working it would suggest that the clock may well just need setting.

 

Click here for the user manual.

 

Check this first and let see how it goes setting the clock for manual cooking.

 

Hope this helps

Let me know how it goes or if you need more help.

Customer: replied 7 years ago.
Sorry, should have said in the original question, i always power it down when it's not in use and hence always use it in manuel mode - any more ideas?
Expert:  Techdesk replied 7 years ago.

Hiya,

When it's first powered up it goes into automatic mode by default.

Can you confirm that the A isn't showing in the clock?

 

Thanks

Customer: replied 7 years ago.
yes
Expert:  Techdesk replied 7 years ago.

Hiya,

Thanks for that.

 

In that case, it would suggest that the thermal cut out has been activated.

 

Isolate the power to the appliance and take it out of it's built in location.

Take the top and rear panels off.

On the rear you should find a small item with 2 terminals attached to the oven housing.

Use a multimeter to determine if this is open or closed circuit.

If it's open circuit, to test further, take the wires and join them temporarily together, insulate and switch on. If the oven works this confirms that this item is at fault.

 

It should be on one of the Neutral wires and may be white (the colours can differ from the wiring diagrams).

 

Have a look, see what you find.

 

Thanks

Customer: replied 7 years ago.

OK....

taken top and back off, checked thermal fuse (small white rectanglular block with 2 terminals which said "20W47ORT" on it - cables where purple for future reference)

and it's closed circuit.

 

Some good news it looks like new inside!

 

As stated in posting the only thing which "should" have happened to the oven during my holiday is it got cleaned, which makes me think the cleaner may have upset something inside the oven while cleaning it, guess either the elements or themocouple as thats pretty much all i can see in there...

 

Hope this helps?????

Expert:  Techdesk replied 7 years ago.

Hiya,

Sorry, It's not an element fault as that wouldn't stop the temperature light or the fan running.

It really sounds like a timer/clock fault.

 

On the rear of the timer/clock, how many wires are there?

 

Thanks

Customer: replied 7 years ago.

Hi,

Theres 6 connectors on the back of the timer circuit board made up of:-

2 off - Purple (single cable in each)

1 off - White and red striped (single cable)

1 off - orange cable and red cable (2 cables)

1 off - red cable and red cable (2 cables)

1 off - White cable and white cable (2 cables)

 

reguards

Expert:  Techdesk replied 7 years ago.

Hiya,

Sorry, the wiring colours don't match the wiring diagram.

Could you upload a photograph of the rear of the timer showing the wiring?

I should be able to work it out from there.

 

Thanks

Customer: replied 7 years ago.
graphic
Expert:  Techdesk replied 7 years ago.

Hiya,

Thanks for that.

Working from the left on the picture.

Take the first 2 connectors off and temporarily join them together then insulate them.

Take the 3rd and 4th connectors off and temporarily join them together, then insulate them.

Apply power and try the oven again.

 

If the ovens work, the timer is faulty.

 

Thanks

Customer: replied 7 years ago.

OK,

Connected two left hand side cables (purple) together

Connected next two cables (red/white and orange+red) together

 

switched on oven, turned thermostate up, switched on mains and put into manuel mode - no change to original problem

 

Sorry, but theres not much left to test i guess!!!!!!

 

 

Expert:  Techdesk replied 7 years ago.

Hiya,

Sorry, I'm at loss with this one.

Everything is testing fine.

I'll opt out of the question and open it to all experts again.

Perhaps someone will come up with something I've missed.

 

I can only suggest checking for more thermal cut outs on the appliance, although there's not one shown in the diagram I have.

 

Good luck with it.

Thanks

Customer: replied 7 years ago.

OK, thanks for your help.

 

All the best,

Andi