Viewsonic Monitor and the text is not black but grey.

Hi.
Please try to connect other monitor to your CPU.because I know the problem is in your video card graphic.also change your screen resolution to 1024 by 768.
if same problem again. need to check-up your viewsonic p75f+ crt monitor. some parts of your vertical video section capacitor leakages.

Failing internally, unless you suspect the cable or graphics card?
Repairs are possible, but unlike the older CRT monitors, expensive and sadly uneconomical. CRT screens do go over time and the loss of a colour channel is usually the 1st sign it needs replacing

Do you mean there is a dark grey outline when using it in 16x9 mode? This happens with my projector too. Try using dark (or black) masking around the screen.

Check the horizondal out put transistor if it is short replace the transistoror or replace the flyback transformer.

Your power supply has gone bad you need to take the back off. Check the power supply look for blown caps the tops will be raised replace them that will fix the monitor.

Burned-out back-light.

Projection TV tubes have a liquid coolant that is used to keep them from overheating. After many years the coolant in the blue and green tubes will become cloudy and cause the screen to look dull, red/orange, etc. You may even see halos around images. 

What you will need to do is replace the coolant and clean the crt. You can get a repair kit from www.TvRepairKits.com that includes replacement coolant, photos. instructions, etc.

It looks like you will have to get the backlight replaced/fixed.

Problem solved! The main power thingy (the thing with the big red wire coming out of it) was all black and dusty. There was 'soot' all over the whole insides of the monitor. I concluded that this monitor should be laid to rest, and a new flat-screen monitor erected in its place.

Your monitor is missing blue drive. Most likely a component failure on the CRT board. Bad color ICs, bad solder connections or defective capacitors can cause the problem.