Connect with us

Microwave oven

Discussion in 'Electronic Repair' started by Retired, Apr 17, 2006.

Scroll to continue with content
  1. Retired

    Retired Guest

    I have a GE microwave oven that just stopped heating. I have checked
    and found the problem to be in the high voltage section. I found the
    high voltage diode shorted and the high voltage capacitor going bad.
    I've replaced both of these, but it still does not heat. When I
    rechecked I again found the diode shorted within 1 minute of running.
    The magnetron tube was replace 3 months ago and the transformer tests
    good. The magnetron tube show no short to case. Also no shorts in
    transformer, and correct ohms on each winding. Has anyone run into
    this, or have any ideas?
    Retired
     
  2. JANA

    JANA Guest

    It sounds like the magnetron is shorting or pulling too much current when it
    is powered up.

    Is for myself personaly, when my personal microwave oven fails, if it is not
    a small easy fault to service, I replace the complete oven. Many of the
    models now carry a 3 year warranty. If you amortize the cost over the 3 year
    period, the cost is very cheap.

    --

    JANA
    _____


    I have a GE microwave oven that just stopped heating. I have checked
    and found the problem to be in the high voltage section. I found the
    high voltage diode shorted and the high voltage capacitor going bad.
    I've replaced both of these, but it still does not heat. When I
    rechecked I again found the diode shorted within 1 minute of running.
    The magnetron tube was replace 3 months ago and the transformer tests
    good. The magnetron tube show no short to case. Also no shorts in
    transformer, and correct ohms on each winding. Has anyone run into
    this, or have any ideas?
    Retired
     
  3. What do you mean by "going bad"?
    Was it heating during that 1 minute?
    There's only 4 parts there - HV transformer, HV capacitor, HV diode,
    magnetron. It's unlikely that the HV transformer could go bad in a
    way that would not result in a blown fuse or lots of smoke.

    The magnetron could be defective and show up only with HV applied.

    What abouut the condition of the waveguide and the rest of the oven?

    --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
    Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
    +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
    | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

    Important: Anything sent to the email address in the message header above is
    ignored unless my full name AND either lasers or electronics is included in the
    subject line. Or, you can contact me via the Feedback Form in the FAQs.
     
  4. Retired

    Retired Guest

    The capacitor showed a short to case after running for about 2
    minutes, but would again test OK after being off for a while. The wave
    guide and the rest of the oven look A1. The magentron look good also.
    No ;I got no heat in that 1 minute that I ran it. I had a cup of water
    in it, and it stayed cold. I am beganning to think it is the magnetron
    even though I can not prove it.
     
  5. Retired

    Retired Guest

    The capacitor showed a short to case after running for about 2
    minutes, but would again test OK after being off for a while. The wave
    guide and the rest of the oven look A1. The magentron look good also.
    No ;I got no heat in that 1 minute that I ran it. I had a cup of water
    in it, and it stayed cold. I am beganning to think it is the magnetron
    even though I can not prove it.
     
  6. Retired

    Retired Guest

    The capacitor showed a short to case after running for about 2
    minutes, but would again test OK after being off for a while. The wave
    guide and the rest of the oven look A1. The magentron look good also.
    No ;I got no heat in that 1 minute that I ran it. I had a cup of water
    in it, and it stayed cold. I am beganning to think it is the magnetron
    even though I can not prove it.
     
  7. BR

    BR Guest

    I used to fix them years ago. I made a resistive divider which I could
    use to measure the high voltage at the cathode using a conventional
    voltmeter. If the heater windings are OK and the voltage is about 2500
    (IIRC) then replace the magnetron.

    Cheers.

    Bill.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-