What is probable cause of red screen display

Sounds like display panel fault. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

Check for any loose solder terminals at the video output board. This board can be located at the neck of the picture tube, plugged directly to it. Check all the solder terminals there. Re-solder all the suspected solder terminals, especially to the red out transistor leads soldering. Check the load resistor to that transistor for open circuit. Check this link for more details. It has details about, one color predominant screen faults and rectifications.

Did you set ur resolution screen setting higher than 1024 in ur computer panel resosulion setting?Yes than that is ur problems right there.CRT monitors modes are based on old technologies ,CRT monitors can't go up more than 1024 resolution setting.Setting resolution more than 1024 resolution for CRT models monitors will have thesse causes.The screen resolution on the screen will shrink and get smaller or will not have video resolution on the CRT monitors screens at all.Only LCD or LED monitors models can support and go higher than 1024 resolution setting has none of these causes.Time to upgrade for a new monitors technologies like LCD or LED monitors models.

Is this a projection/plasma/CRT?

the RGB controls that you found were those the focus or were they the screens? There should be small switches like that (variable resistors) on the CRT circuit boards themselves. The crt circuits are attached to the crts end . You can gain access to them by removing the speaker grille and access panel in front. I am not sure of the resistors number for that model, however these are always brown resistors and and you will see that one leg is attached to the runner right next to that control switch. I will try to locate the service info for that cahssis V18 and repost if I can locate the info.

the CRT is the picture tube. If you cant control the red alot of times its the picture tube (CRT) that has shorted causing the screen to take on the dominant color of the affected tube.

Your set doesnt have a color wheel you have 3 CRTs instead. Try turning down the red drive on the red crt circuit board that should help if not check the resistor that is connected to the red drive switch Vasriable resistor(switch) that is probably open if not the crt is probably at fault. If you need more info let me know.

Your problem sounds like it has to do with beam landing, or purity.
In a CRT type tv such as yours this can have many causes, some of which I'll describe.
- The CRT (picture tube) is magnetized, possibly by speakers being placed too close to the tv. Turning off an item such as a vacuum cleaner in close proximity to the tv can also cause the crt to become magnetized.
- The auto demagnetizing circuit has malfunctioned and requires a tech to repair
- The CRT has developed an internal fault and would need to be diagnosed/replaced. This is not worth the cost of repair.
- The yoke and/or beam landing magnets have become loose or faulty. This is internal and would require a tech to confirm or repair.

The only fault which you may be able to fix is if the crt has become magnetized. Check for sources of magnetism close to the tv. That would be such things as speakers or anything with a permanent unshielded magnet. TV's with CRTs have a circuit which demagnetizes the crt at each cold start. Turn the tv off and leave it off for 3 hours and then start it. If the crt is too magnetized or there is a problem with that circuit this may not work. You can also try a different placement, the ideal being the front of the screen pointing either directly north or south.

first try going to the menu on the tv and adjusting the red blue and green tint....if not the u need to remove the front pannel and move the the the top left knob on the setting to lower the tint...

in Monitor CRT Red-Blue-green cathode guns are there.. Mixing of these colour we can get the original colour chrominace technique. if any of the colour gun is faulty we would get more REad or blue or green picture. Measure RGB voltages. you can verfify which gun is faulty. if then check RGB processing circuits. Else there might be problem Chrominance colour decoder system. Contact service centre