View Single Post
  #6   Report Post  
Posted to sci.electronics.repair
Sam Goldwasser Sam Goldwasser is offline
external usenet poster
 
Posts: 142
Default Microwave schematic

"Silver Surfer" writes:

I've looked at just about every conceivable location inside and outside the
cabinet but have not located a schematic.

It's my daughter's microwave. Complaint was that it keeps shutting down
shortly after starting to heat something. Problem has been around awhile
but kept getting progressively worse until now it's just about useless to
cook something.

Brought it home with me. Tried it out. Worked perfectly quite a number of
times. Took it apart just to look for something that could be causing an
intermittent. Found nothing. Put it back together. Oops. Problem back
with a vengeance.

Tore it apart again. Checked lots of connections and TCOs with my ohmmeter.
Examined circuit board with a high intensity light and a magnifying glass.


Underneath I assume? It does sound like an intermitten connection but
an ohmmeter probably won't find it. Only a really close examination.

While highly unlikely, check or replace the fuse as well.

Nothing turned up.

Unplugged the HV transformer primary and put it through its paces.
Everything worked flawlessly(except the heat of course).

Connected the HV transformer again. Voila. It's working normally again!
My concern is that it will go back into the failure mode sooner or later,
because no smoking gun has shown up.

When it was acting up it made me suspect that the board was losing power
because when it shut off the digital display required me to enter the time
and date just like it does after it's unplugged.


An aside to Mr. Goldwasser:

Your excellent article on microwave repair has been an enormous help to me.
Thanks for sharing your extensive knowledge with the rest of us.


Thanks.

--- 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.

"Silver Surfer" wrote in message
...
Folks,

My searching on Google has come up empty. Do service manuals and
schematics actually exist for a GE microwave oven JVM1650BH03? If so
where might I acquire such material?