On 1/14/2005 8:34 AM US(ET), Charlie Bress took fingers to keys, and
typed the following:

wrote in message
roups.com...


Charlie Bress wrote:



This is a Panasonic microwave that is about 10 years old.
It works just fine.
The problem is that it has become fussy to open
In the picture at the link you can see the inside portion of the gray
opening button. It has a small projection that lifts the part of the


latch


mechanism that is white.





Try a Google Groups search of sci.electronics repair for Panasonic
microwave interlock ?

Panasonic's National Parts Center sometimes has very old parts at
reasonable prices, but MCM Electronics or Fox International may have
them as well.

The electrical portion of the door interlock mechanism can be fully
tested with the oven unplugged, by using an ohm meter or low voltage
test lamp on its microswitches (to prevent damage to any electronics,
unplug the switch wires first, noting where they went originally).

Does the mechanism bind less if you retract the microswitch (maybe 2
switches since manufacturers don't want door interlocks to fail in a
dangerous way) manually and then operate the interlock? If so, then
clean the plastic where it rubs against the switch, and it's possible
the plastic should be greased there. Switches and nylon (white
plastic) can withstand common automotive lithium grease, but silicone
grease is more inert. If that doesn't help, I might try disassembling
the mechanism and clean everything (alcohol or brake parts cleaner).
If the parts were originally lubricated, apply lithium grease to them.
Cracks in nylon can't be fixed well with glue but only by heat welding
them with a soldering iron (clean tip). If filler plastic is needed,
shave slivers off the nylon parts because other types of nylon, such as
that in nylon wire ties, probably won't stick well. The grey
pushbutton is probably made of ABS, which is best repaired by solvent
welding it (hobby shops sell liquid glue, but lacquer thinner or
carburetor spray work equally well). Solvent glue should be allowed to
evaporate for at least 12-24 hours before subjecting the plastic part
to stress again. If solvent doesn't affect the grey plastic, then most
likely it's polypropylene, which is also best repaired by heat welding
it.




I had considered silicone spray, but I am always hesitant to just rush in
without the voice of reason backing me up.
Nothing seems to be broken. A little judicious silicone may very well prove
to be the answer.
I have made a quick search for part replacements , but that has been stymied
by the inability to locate a model number anywhere. I have looked on the
door frame, the back of the box and the bottom. All I have found are the
safety and regulatory labels.

Thanks for a helpful post as compared to some of the drivel that gets
posted.

Charlie


I have never seen the inside of a microwave, but I am usenet compelled
to respond. :-)
It appears that the dark grey thing at the bottom left is the door button.
What happens if you operate the button and/or door while observing what
happens inside? Does anything appear to be hanging up?
Does that tab at the top right of what may be the button, and which
appears to have a clearish pad on top, release the whitish nylon
projection just under the screw? Is that clearish pad cracked (it looks
like it may be in the photo)?
Is that door button thing hinged underneath, and is the hinge just a
thin bendable piece of plastic? Is the 'hinge' cracked?
Well, that's it for me. Good luck!



--
Bill