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Tech Michael
Tech Michael, Home Appliance Technician
Category: UK Appliance
Satisfied Customers: 9137
Experience:  20 + years of experience repairing all home appliances, from Micrwaves, Ranges, Washers and Dryers
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Got a Bosch Microwave HMT35M653B/03 and it stops after about

Customer Question

hi. got a Bosch Microwave HMT35M653B/03 and it stops after about 30 seconds, fan and light works but no heat (doesn't warm butter etc). Thought it may be a fuse,, ?
Submitted: 1 year ago.
Category: UK Appliance
Expert:  Kelly replied 1 year ago.

Hi, welcome to Just Answer. My name is ***** ***** I look forward to helping you! The fact that it stops after 30 seconds suggests that it is overheating or the main control is having trouble. It would not be a fuse. If you unplug the appliance for a few hours, any change when it is plugged back in? What exactly happens when it shuts down? Does the display go dark or just count down and stop?

Customer: replied 1 year ago.
Hi Kelly. It was unplugged overnight. I plugged back in. Time shows. I put a knob of butter in a bowl. Turn on. Set 1 minute on high. Light comes on in the cavity. Press start. The fan goes on and timer counts down for between 20 to 30 sec. The cavity light and fan then goes off. The timer now displays 1min again. This happens every time. I don't notice the magnetron activating but may be mistaken. Thank you
Customer: replied 1 year ago.
Ps. The butter does not melt at all.
Expert:  Kelly replied 1 year ago.

The erratic operation of the timer display suggests the electronic control is having trouble. It will likely need to be replaced. It is going to be difficult to determine whether it is the interface board or the relay power board, though. Given the erratic display, I believe the interface board is faulty, part number 00685475.

Customer: replied 1 year ago.
Hi Kelly. Ordered the part so week let you know how it goes when it comes next week.
Expert:  Kelly replied 1 year ago.

Sounds good, thank you. Have a great week!

Customer: replied 1 year ago.
Hi Kelly. Spent £180 on the spare board. Replaced it and the exact same problem occurs. Counts down to 36 sec then stops, as above.
Expert:  Kelly replied 1 year ago.

I am sorry you are still having issues with your microwave. If the problem still exists, the main power relay board is likely bad. This type of issue can be hard to diagnose with the several different electronic controls in the unit.

Customer: replied 1 year ago.
OK. I'll go ahead and order the power module board 00654150 (replaces 00653689).
Expert:  Kelly replied 1 year ago.

Thank you, ***** ***** posted. Electronics can be difficult to diagnose.....

Customer: replied 1 year ago.
Hi. Spent £185 on the new power module board (as above) and is not fixed it. I tried some additional tests to try and narrow it down. On 1000W 600W or 360W power it cuts out after 30s on 90W and 180W it will carry on counting down indefinitely but still does not heat water up or melt butter.
Expert:  Tech Michael replied 1 year ago.

Hi different expert here, I'm tech Michael, this is a bad magnetron,not the main board.

Replace that and your problem is solved;-)

I have been fixing microwaves for over 25 years and I know the symptom well.

In any case, I will stick with you until this is complete.

Please rate kindly thus far, it won't cost you anything to rate my service to you kindly,

Then you can reach me by simply replying to this message anytime.

Thank you and have a nice day!

Tech Michael

Customer: replied 1 year ago.
Hi. Parts arriving today. Will be fitted at weekend. Keep you posted. Thanks
Expert:  Tech Michael replied 1 year ago.

Hi I'm tech Michael, I see you on here, if you have any questions or problems when you make the repair just let me know, I will help ;-)

I will stick with you until this is complete,

Please rate kindly thus far, it won't cost you anything to rate my service to you kindly,

Then you can reach me by simply replying to this message anytime.

There is no cost to rate ;-)

Thank you and have a nice day!

Tech Michael