Microwave oven shutdown problem

Hello. This is a Hardstone brand microwave oven board. It had a power failure problem. The power supply was broken and the power problem was solved by replacing the switching IC. The 12 and 5 voltages are OK. Now the device does not turn on when the power button is pressed. I tested the power pins of the display board ICs, which are the microcontroller and LED driver, and they all have voltage and none are shorted. Why does the device not turn on? How can I test the microcontroller other than by testing the voltage? Thanks.
18:41
 

Attachments

  • ۲۰۲۵۰۴۱۴_۱۸۲۶۳۳.jpg
    185 KB · Views: 20
  • ۲۰۲۵۰۴۱۴_۱۸۲۶۲۶.jpg
    216.4 KB · Views: 16
  • ۲۰۲۵۰۴۱۴_۱۸۲۶۴۴.jpg
    255.1 KB · Views: 21
  • ۲۰۲۵۰۴۱۴_۱۸۲۶۵۶.jpg
    251.1 KB · Views: 22
  • ۲۰۲۵۰۴۱۴_۱۸۲۶۵۲.jpg
    264.2 KB · Views: 21
  • ۲۰۲۵۰۴۱۴_۱۸۲۷۰۵ (1).jpg
    210.4 KB · Views: 16
  • ۲۰۲۵۰۴۱۴_۱۸۲۷۰۵.jpg
    210.4 KB · Views: 15
  • ۲۰۲۵۰۴۱۴_۱۸۲۷۱۱.jpg
    280.7 KB · Views: 17

Hi,

What caused the failure? That could tell us where to look.

You would probably have to know what each pin of the controller IC was used for, but if you can narrow it down to just the pin that turns the power elements on maybe you could check that.
 
Cookies are required to use this site. You must accept them to continue using the site. Learn more…