How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • Go back-and-forth until satisfied
    Rate the answer you receive.
Ask JamesI Your Own Question
JamesI, Handyman
Category: Appliance
Satisfied Customers: 6573
Experience:  I have repaired and maintained numerous items over the years, from fridges to freezers, radios to TV's.
Type Your Appliance Question Here...
JamesI is online now

We have a Panasonic Microwave NN-ST452W that won't start the

Customer Question

We have a Panasonic Microwave NN-ST452W that won't start the cooking process its only 2 years old
JA: What device is not powering up?
Customer: Panasonic Microwave NN-ST452W
JA: How long have you had your NN-ST452W?
Customer: 2 years
JA: What have you tried so far with your Panasonic product?
Customer: total power down over night, checked all micro switches on door mechanism
JA: Anything else you want the Electronics Expert to know before I connect you?
Customer: no that's all
Submitted: 7 days ago.
Category: Appliance
Customer: replied 7 days ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call.
Customer: replied 7 days ago.
Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 7 days ago.
everything works normal up to pressing start button then the turn table works but the cooking time on the screen doesn't count down and it doesn't heat the food
Expert:  JamesI replied 7 days ago.

Hello and welcome to JustAnswer!
This is James, I'm an appliance repair technician with over 10 years of experience, and I'll be assisting you today

Sorry to hear your appliance is having issues, please stand by while I find the answer for you, this is not an immediate service however I will try and respond as soon as possible.
To confirm the interior light comes on as you open the door, goes off when closing the door and you can set the time, but when you press start it will not count time the timer and commence the cooking process?

Customer: replied 7 days ago.
After pressing start the light goes out, the display panel dims and says “close the door” , I have checked all three micro switches with a meter and they all work. Up until now it has been working but failing occasionally, now not working at all. This started several months ago then corrected itself and it started happening again just recently.
Expert:  JamesI replied 7 days ago.

If you are confident the switches a providing the correct input (door closed), but its still thinking the door is open and the wiring harness is intact then it has to be a fault on the IC of the PCB where its not reading the input from the switches correctly.

You will see from the spares diagram here there are only three contact switches so confident you haven't missed any.

Customer: replied 7 days ago.
Have had all three out, meetered and away from there location taped together and operated by hand and still the same
Expert:  JamesI replied 7 days ago.

So that means the PCB is at fault.

Customer: replied 7 days ago.
Is that the board behind the front panel?
Customer: replied 7 days ago.
is that the board behind the front panel?
Customer: replied 7 days ago.
I have paid for a phone call but in the mean time is that the boards behind the front control panel?
Expert:  JamesI replied 7 days ago.

Offers for calls are just automated adverts, you can discard them if you are happy for a typed response (and do not want to pay the additional fee). However it can take time for experts to respond, please be patient and an expert will respond as soon as possible.

To clarify it would be the PCB behind the keypad yes, however with these budget appliances its generally not economical to repair them.

Customer: replied 7 days ago.
I think I have paid when maybe it was not needed!!!!!!! is it possible for a part number for this component or more parts data sheets including this PCB??
Expert:  JamesI replied 7 days ago.

You need to get an appliance engineer to attend as to complete the setup the appliance will need tested and this requires specialist equipment.

Customer: replied 7 days ago.
Many thanks James, I have found a board on the internet for 11.99 will install and give it a try, if it doesn't work then I will scrap the microwave under duress. thanks for your trouble and help.