About X-RAY protection pin
If you are repairing CRT TV or Monitor, you will notice that there is a pin called as x-ray protect in one of the pins in the horizontal/vertical oscillator ic or even in Jungle chip (please see pin 2). The function is to detect any abnormal voltage feedback by the flyback so that if the feedback voltage is too high, it will shutdown the internal generator and no horizontal output pulse will be produced. If no output pulse the HOT will not switch and if the HOT does not switch the flyback will not be energized thus no high voltage produce.
If you want to isolate the shutdown problem you cannot just remove the pin of the x-ray protect and expect it not to shutdown. If you referring to older model then YES, by removing the x-ray protect pin the equipment will not shutdown. But then again it can be dangerous to you or to the user if you just return the set back to the customer. Why dangerous to you, because when you disable the x-ray protect pin and continue to troubleshoot you could be exposed to x-radiation.
If the TV or monitor have shutdown symptom, the first thing to check is if the B+supply voltage is too high or not. If it is too high then definitely it will shutdown and you need to check on the optoisolator circuit. The next thing to check is the safety capacitor. If the capacitor value is out, high voltage can be increased thus shutting down the equipment (thanks to the x-ray protect circuit). A bad or leaky flyback transformer also could cause shutdown problem. If you are repairing CRT Monitor and the internal capacitor in the flyback transformer have an open circuit, it could also cause shutdown problem.
Conclusion-if you want to defeat the x-ray protection pin for temporarily troubleshooting it is ok but not too long and please do not entirely defeat the pin (without finding the real cause) and send the equipment back to customer. This will truly harm the user.