[sexobon]

Originally Posted by Glinda

Ah. Now this makes perfect sense to me. I was sure there was a house wiring component to this mystery. Thank you!

Originally Posted by tw

No house wiring is involved in this mystery (if AC electric lights do not flicker or change intensity when major appliances power cycle). Posted were electrical fables invented by many who forgot to first learn how electricity works. ...

If you read what was written, with comprehension, you'll see that no one was blaming house wiring for the malfunction.

Originally Posted by tw

… If you had a surge, then a microwave is damaged - no longer works. And some of other less robust appliances (ie GFCIs, clocks, central air controller, door bell) are damaged. ...

False. That's only if there's a large surge:

Why worry about power surges?

Your home is filled with items susceptible to power surges. Anything containing a microprocessor is especially vulnerable - the tiny digital components are so sensitive that even a 10-volt fluctuation can disrupt proper functioning.

Microprocessors are found in hundreds of consumer items, including TVs, cordless phones, computers, microwaves, and even seemingly "low-tech" large appliances like dishwashers, washing machines and refrigerators.

Large power surges, as with a lightning strike, can cause instantaneous damage, "frying" circuits and melting plastic and metal parts. Fortunately, these types of power surges are rare.

Originally Posted by tw

… Not one reason is given to suspect house wiring or a surge. So those wild speculations are binned immediately. ...

Again, no one said they suspected house wiring was the cause. As for there being no reason to suspect a surge - False:

Internal power surges

More than half of household power surges are internal. These happen dozens of times of day, usually when devices with motors start up or shut off, diverting electricity to and from other appliances.

Refrigerators and air conditioners are the biggest culprits, but smaller devices like hair dryers and power tools can also cause problems.

External power surges

An external power surge, stemming from outside your home, is most commonly caused by a tree limb touching a power line, lightning striking utility equipment or a small animal getting into a transformer.

Surges can also occur when the power comes back on after an outage, and can even come into your home through telephone and cable TV lines.

And then there's a potential problem from cumulative damage that can make a very old microwave more susceptible to a small external surge before or after a power outage:

Low-level power surges won't melt parts or blow fuses, but they can cause "electronic rust," gradually degrading internal circuitry until it ultimately fails.

Small surges won't leave any outward evidence, so you may not even be aware they're happening - even though they may occur dozens or even hundreds of times each day.

Obviously, tw has acquired "electronic rust," which gradually degraded his internal circuitry and it is ultimately failing … not one brain left in his poor old head.