We have a big screen rca tv , one of the older models, it has worked fine up until now. The picture is stretched out and we can't even see what channel we want to watch on the guide it need to come in on both sides

Check the convergence IC's for cold solders, check for leaking capacitors in the area. Check the voltage regulator with a Variac.

Usually these sets just need the 2 big convergence IC's replaced with new ones. Clean all 3 picture tube lenses, mirror and screen. Get the original RCA remote that came with the set and MANUALLY align the convergence.

Rarely the bow on the bottom of the screen is not repairable.

RCA projection TV was working great and then suddenly would no longer turn on like there was no power to the unit.

I have a screen protector from a 1998 RCA older model big box style tv

Your high Voltage anode button that connects into Picture tube may have came lose Rember Picture Tube if not broken Holds 36,000 volts if not discharged, Have you Look under chassis to see if board it cracked? Sounds like your FBT?

streched which way... up down left and right
try pushing left or right arrow keys on remote to change format.

when i turn my big screen on it wont come on you can here the sound but the picture is still black

NO audio and no picture .... no power to on - off button. Checked outlet and it is good .... cable connection good - checked with another tv....

I replaced the screen on my 62 inch projection TV for about $50 and the the picture quality is good! Have a sheet of plexiglass cut to the EXACT size needed. BEFORE installation it MUST be frosted on both sides by either a fine particle sandblaster or by sanding it VERTICALLY on BOTH sides with a power sander and a fine grade paper.
If this is only an OUTER protective screen and the image is projected on the inner screen then DO NOT frost the replacement screen, just install it.

the High Voltage splitter needs to be replaced

Need model # more than likely you have no high voltage going to crt. It could be horizontal output and starter caps and much more. Is there any lights that stay on when pressing power?