My blown fuse Experience With a Sharp Carousel Microwave Oven (Model R-330AK)
[cira Dec. 1997]:
My wife told me the microwave oven didn't work. Checking it out it seemed to be
a typical fuse problem. A few
years ago we had a similar problem with this same oven. However, after I
replaced a clearly blown fuse (20 amp,
ABC type) the oven would not work. It was as if the fuse had blown again (it
hadn't!) In frustration, I took it
to the Dealer's Repair Shop to have it really fixed. When I went to claim it a
week later I was told I had
damaged the Display Panel in my attemped fuse repair and the bill came to $145!
I said, I didn't care if the
display worked perfectly. I just needed the basic power functions. $60 allowed
me to have just the fuse replaced!
This time I knew the fuse had blown and I had not damaged anything within, but
the replacement fuse made no
difference. Your web site info got me to probing the circuits with my Ohm
Meter. There was continuity through the
power cord prongs to the leads inside of the cabinet. Continuity on the black
wire ended on the output prong of
some kind of white plastic device screwed to the inside back of the cabinet. I
thought this might be some kind of
safety power isolation device. Once I removed this device, I could see it was a
Cutoff Switch which would cut
power to the oven if the lower left cabinet screw was loosened (required to
open the case). One of the sheet metal
screws was two millimeters longer than the other three! If you didn't notice
where the long screw came from, you
have only a 25% chance of fixing your microwave oven fuse. Now, when you take
the oven to your friendly repair
man, he knows you had the case open (forbidden to all but PROPERLY QUALIFIED
REPAIR PERSONEL).
I don't think Sharp Company planned to give their customers a Golden Screw Job
for $1 fuse replacement. Their
lawyers probably insisted this was a way to protect 75% of the DIY'ers from
injury and sueing Sharp for not doing
something to protect them. Paranoid? Who, me? Thank you for your site.