It's a common problem, I see it almost daily in my work.

The servo loop will only try to drive the motor in one direction unless the position of the mechanism changes, so unless the 4558 failed catastrophically and pulled in the opposite direction, nothing would've happened to Q510.

Ahh, well that'll kill them too for sure, heh.

Looked it up, yes that's one of the complementary output transistors for the "cot" motor, which is responsible for flipping the tape around. That mechanism is notorious for lubrication failure and maladjustment. It must have good lubrication and be properly adjusted or it burns the transistors.

Easily substituted with other types, but it's important to find out why it's shorted in any case.

This looks like something they would do in Wallace and Gromit.

Probably the easier way to make an accurate comparison is to heat the room to the same degree, under the same conditions, using resistive heating, and compare the energy consumption of both methods directly against one another.

You must measure the temperature rise and the airflow to get a useful number to compare against the energy consumption, and it must be done with a temperature probe that measures the air, not a surface temperature measurement as you could be picking up radiated compressor heat.

Hmmm... Onto my next curiosity... What is Zenly?

What is it supposed to actually be?

Sadly I think many folks convince themselves that something is life-changing when it isn't necessarily so.... often it seems that it's for nothing more than to fit in, to feel one's doing what's expected...

A kinky kidnapping sounds like a lot of fun.

I really would love to meet your two squeaky horses.

Core is unendingly fascinating.

I should finish getting my 8/A going.