Using TV with the back cover & high voltage cage cover removed
 

If the TV is backed up against the corner of a wall with a small gap between the back of the TV and the wall, is it safe to run the TV without the back on AND without the high voltage cage cover removed? X-rays travel in a straight line, so the x-rays that would have been blocked by the cover will just hit the wall behind the TV. No pets or children would be in the room either. The reason why I'd consider doing this is because it would help with cooling the inside of the TV, especially the flyback transformer.

If you're sitting more than 3' away from the set even if the X ray leak is pointed at you it probably will be unmeasurable. Air attenuates X rays.

You could also put some small holes at the top and bottom of the cage and blow in the bottom of suck out of the top with a small fan. I typically on transformer powered sets rectify the heater to get 6V DC and use that to power a small 12V computer fan at half speed for quiet.

I personally wouldn't operate a TV set, monochrome or color, without the HV cage cover in place, due to the shock and X-ray hazard. X-rays were a hot topic in TV about 30-some years ago, especially with color televisions which apply very high voltage, on the order of 20-30kv or more, to the 2nd anode of the CRT. I remember reading at least one article in an electronics magazine (I don't recall which one, as I write this) from the 1970s which went into some detail as to the X-ray hazard; this article mentioned how dangerous X-rays from color TVs were, and that parents should tell their children not to sit too close to the screen, again due to the very real danger of X-radiation from the CRT and from other parts of the HV plant, including but not limited to the HV regulator tube. The flyback transformer itself can also generate X-rays in a color TV, especially if the HV regulator tube is weak or nearly dead. Operating a color television without the HV regulator tube is dangerous as well, as the flyback will now generate as much 2nd anode voltage as it possibly can before burning out or destroying other parts of the HV plant (until or unless the HV fuse or the television's own line fuse blows first, of course).

Delete duplicate post.

I have heard of the mods to add a fan, but I wanted to try a more simple approach first. I have a Geiger counter that can detect x-rays, so I will just measure using that. With the back cover off, there is still metal shielding on all sides of the x-ray generating tubes except the back. So the x-rays can only shoot the wall behind the TV, and since I have the TV in a finished basement, the other side of the wall is dirt. So x-rays, physically can’t be a problem.

I own several GE Portacolor TVs and the early chassis design had a metal cover on the flyback cage opening, but later models removed the metal cover, exposing the HV rectifier and flyback. GE could use this design because they use a rectifier tube with built in shielding and while the diode can handle up to 25kv, they only run it at 17kv. So the tube’s shielding and the plastic shell of the TV is enough to block the 17kev x-rays.

This shows that during the late 1960s, TV designers knew about flyback overheating and their solution was to just remove the high voltage cage cover.