In sci.electronics.repair, on Wed, 30 Nov 2016 19:33:00 -0500,
FromTheRafters wrote:

Frank formulated the question :
On 11/30/2016 5:45 PM, FromTheRafters wrote:
micky explained on 11/30/2016 :
How long does it take a microwave oven to warm up?

The energy transfer is nearly immediate. The oven only warms up because
of the food warming up.

Some items which I microwave would end up having cold or cool spots, so
I used to cook say a three minute item by cooking for two minutes and
then allowing the heat to spread for a couple of minutes, and then zap
for another minute or so.

I now have a new microwave oven with a turntable (the other had a
reflector) to help avoid the spottiness. The ovens power output is also
an important factor to consider.

I find it easier to microwave for longer periods of time at a lower setting
to get even heat.

Yes, the new MW oven has programmable settings for power level and rest
periods and such for better results. The old one only had a single knob
with minute marks on it and a bell that softly, almost inaudibly, went
'click' when the time expired.

The old one is 26 years old, but it still works.

I had an Amana Model 2, that looked just like the drawings of microwaves
that were used for decades. It lasted many years. I got it used around
1975 and met its earthly demise around 2000. . Although the insulation
on the diodes had failed** and it sparked, so I covered the open parts
with GE silicon sealant, and something else I fixed, and eventually the
power transformer broke, I think it was. They wanted 300 dollars for it
and my pointing out that they should take 80 since I coudl buy a new one
for 80 didn't help. They lowered the price to the repairmans price of
200 roughly.

**Amanda didn't want to send me a schematic. I had to beg, and promise
I knew what I was doing and wouldn't kill myself. She relented.