I recently bought an Atari SM144 monochrome monitor so I could play with an old Atari ST. It works to a certain degree, it turns on all good and I can play for a while, but after some time it gives off an ionising/burning smell.
It working (ignore the refresh rate discrepancy, it's a solid picture my end)
Then after let's say 5-10 minutes, maybe less if I turn off the monitor by the switch on the front, and then turn it back on, I get lines like the following
Any ideas what this could be?