monitor replacement

The framebuffer may be set to a particular res the monitor can't handle.

You can use a serial console to reset the res, and see if the monitor comes up ok.

hello,
Assuming that you got a new monitor (if you didn't it could be a capacitor, in which case, you should buy rubber boots and electrical contractor gloves if you want to try and fix it), it depends on the brand. If you are operating it in the vicinity of a lot of cameras, it could be electrical interference.
You need to tell the computer what kind of monitor it is (start control panel monitors), then you can adjust the refresh rate. It also can be done with the controls on the monitor itself.
So here's what you do :
1) Delete all other monitor data (above)
2) Select the exact brand of your monitor in "add hardware" (look on the back of the monitor)
3) Examine all monitor hardware controls
4) Look up the model on the web (Mitsubishi.com) and download the manual for it
5) THEN, AND ONLY THEN, if you cannot set the refresh rate on the monitor, do "Help, Search, refresh rate" to set the refresh rate from the keyboard.

xx
John