AOC L22W898- TV turns on to the default "start up" screen- just a design in light blue colors- then turns off abruptly. Checked caps etc in the power supply and all seems ok. Before the unit went out there were intermittent sudden volume swings for a few days and a slightly dimming picture then while watching it just went off. Should I go ahead and re-cap the power supply?

Change your batteries. Clean the battery contacts. Use a digital camera pointed at the LED on the remote to see if it is working. It might actually be the TV, but it is usually the remote.

This sounds like a common problem on these TVs. Try a factory reset:

1. Press and hold "Menu" and "Channel+" on the TV. (do not use the remote)
2. Using the other hand, press the Power button.
3. A small screen should appear in the top left part of the screen.
4. Using the remote, select "Memory Recall" and Enter.
5. Power off and reboot the TV and Computer.
6. Run channel auto-scan to regain the picture.

The TV is locked.. The message is Bottom Locked.

In the menu system there is a reset (I believe it's all reset, or reset all...something like that) which should fix the issue.If not, leave the TV unplugged for 4 hours and plug it back in then turn it on.

Does it do this in both TV and monitor mode or just monitor mode? If in both modes, the high voltage power supply that provides power to illuminate the screen is probably bad.
Have a repair shop check the high voltage power supply.

If the unit is only a few days old, I'd take it back under warranty for a replacement.

I have an idea what's wrong, but it involves ripping the unit apart and replacing parts, which would void your warranty - meaning if something more serious were wrong later, OR if there is more wrong with it than I think there is, you've lost your protection!
I never advise anyone to void their warranty, but if you REALLY REALLY want to try and fix it yourself, click the reply link here, and I'll help you out.

It might be that the PS3 is sending an incompatible signal to the TV. I'd connect the PS3 using normal RCA jacks, and make sure that the video mode in the PS3 menu is set to auto.

I'm waiting!

- Press Menu
- Press 991
- Go down to Memory recall and press enter
- It will ask you "ARE YOU SURE"?
- Select "Yes" and press enter
- It will take you back the menu screen, turn off the TV and turn it back on

If you still get the sound but nothing on the screen, the backlight inverter may ahev gone out, or bad capacitors in the power supply.
http://en.wikipedia.org/wiki/Capacitor_plague