Toshiba 40 inch tv with picture edges gone.

Fault to its main board. Short circuited component/s at it. Contact any service technician; or the authorized service center. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/ . In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

your controlles on the tv set itself goes faulty simply spray some switch cleaner in buttons should sort you out

Do you live in an apartment? Could be a neighbors remote interfearing with your TV.

Do you have sound? What you are describing sounds like a fault in the back light circuit

if it is with hdmi input call toshiba--free software upgrade

You may have failing T-CON board.
Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide

http://s807.photobucket.com/home/budm/allalbums

http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com

Try updating the firmware to version 1.05 from this website http://support.toshiba.ca/support/ceg/downloads/all/view.asp?docid=D000020

Sounds like firmware problem if it is still covered by warranty the manufacturer can replace or sens you a usb with firmware update on it speak to your dealer about your warranty. If not covered let me know and i try find update for you.

That I don't think you can do - the CC is fed by the digital tuner, while the subtitles are fed by the DVD player.

FROM THE TOSHIBA MENU, (FIRST MAKE SURE YOU ARE SET TO
THE HDMI PORT THAT THE XBOX IS PLUGGED INTO) THEN SELECT
HDMI SETTINGS, UNPLUG HDMI CABLE FROM THE TOSHIBA TV (LCD
FLAT, MINE IS A 42") WAIT FOR THE SETTINGS TO HIGHLIGHT OR NOT
BE GRAYED OUT, THEN TURN OFF THE THREE SETTINGS, FOR COLOR
AND LIP-SYNC., SCROLL DOWN AND PRESS THE RESET BUTTON,
WAIT FOR MESSAGE TO APPEAR. TURN OFF THE TV AND PLUG IN THE XBOX.
TURN EVERY THING BACK ON. SEE IF IT WORKS.
NOT ALL CABLES ARE THE SAME AND NOT ALL TVS ARE THE SAME.
READ THE TV OWNERS MANUAL CAREFULLY, (RTFM), I FOUND A NOTE ABOUT
THESE SETTING ON THE SPECIFICATIONS PAGE.