1942 Monitor goes dark

[JimS]

There are a lot of things that can cause this. One thing I've seen a lot is bad solder joints on the flyback transformer. The flyback vibrates a bit and can sometimes crack the joints. They break and arc & burn. It's easy to resolder them... but you have to be careful of the possibly lethal voltages in there which can hang around long after it's been powered off.

[JimS]

Yup, I believe this happened to my 1942 and I had to retouch all the solder points on the board at the back of the CRT.

As mentioned, you have to be careful though because there are some lethal voltages in there.

If you plan to open up your monitor then read about the dangers of flyback transformers.

I'm not sure how long they hold their charge - days?

At least days... It's the CRT that holds the charge. If you're careful, you can discharge that voltage with a grounded screwdriver under the HV lead at the CRT.... I don't recommend it unless you're experienced with it.