Hi,
I opened my microwave today, placed some stuff in and while the cover
was still open i plugged it, then it blowed with a blue flash. It
doesnot run when plugged so that's so strange. When i checked the
general fuse of the house, it was down. Shouldn't it have an internal
fuse?
Anyway, i plugged it back and tried, it runs fine but what shall i do?

Thanks.

It sounds like a major short in the microwave oven. If you are not
trained in this type of service, I would suggest that you get the
microwave properly checked, or retire it and get a new one.


Jerry G.
======

Hi!

As a safety precaution, some microwave ovens are designed with multiple door
switches. Sometimes one of these is intended to short out the AC power going
into the oven if all the switches don't work precisely as they should.

I think it is very likely that this has happened to you. Why? Either the
mechanical linkage in the door didn't engage the switches in the right
order, or a switch has gone bad. Check the latch pins on the door...make
sure they are all there and none are broken or bent. (If you find broken or
bent ones, fixing them should solve the problem...as long as you can find
any broken pieces.)

I've repaired microwave ovens with this problem before. Sometimes the
switches go bad.

***BE EXTREMELY CAREFUL*** if you think you have the skills and desire to
open your microwave oven for service. A mistake made while working on a
microwave can be immediately deadly. Therefore, if you don't have experience
with electronic repair, and high voltage circuits, don't even try this.
Chances are that a repair shop could solve this issue for you quickly.

Oh, and yes...every microwave oven I've ever worked on has had an internal
fuse. However, it has been my experience that the house fuses usually blow
first. I don't know why this would be.

William

writes:

Hi,
I opened my microwave today, placed some stuff in and while the cover
was still open i plugged it, then it blowed with a blue flash. It
doesnot run when plugged so that's so strange. When i checked the
general fuse of the house, it was down. Shouldn't it have an internal
fuse?

It should but that won't necessarily blow first.

Anyway, i plugged it back and tried, it runs fine but what shall i do?

As was recommended by another reply, it should be checked out. Most likely,
there is a problem with the door interlock switches, easy and inexpensive to
repair. But given the cost of microwave ovens these days, replacement
may be a better option.

--- 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.

Thanks for the replies. I was going to call a service but i just
noticed that it's internal lamp is dead now.
Is it possible that a light source can cause a blue flash and fuse
problem?

writes:

Thanks for the replies. I was going to call a service but i just
noticed that it's internal lamp is dead now.
Is it possible that a light source can cause a blue flash and fuse
problem?

The blue flash certainly. In fact, that's probably the only thing you could
see from inside the oven chamber.

In the act of blowing, some lamps can result in a dead short momentarily
so it's possible

--- 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.

wrote:
Thanks for the replies. I was going to call a service but i just
noticed that it's internal lamp is dead now.
Is it possible that a light source can cause a blue flash and fuse
problem?



Yes, many times when an incandescent lamp fails it strikes an arc. It's
quite common for it to kill dimmer switches that way.

Hello, !
You wrote on 22 Jan 2006 05:47:43 -0800:

a Thanks for the replies. I was going to call a service but i just
a noticed that it's internal lamp is dead now.
a Is it possible that a light source can cause a blue flash and fuse
a problem?#

Yes absolutely, every time a light bulb blows anywhere in my house, I have
to re-set the overcurrent trip.


With best regards, 3T39. E-mail: