All the lights are flashing and it says turn power off and then on. I did that and the same thing keeps happening

Backlight video board,have prob.keep happening must change.

Same thing just happened to mine. I think these replacement lamps (L2114A) are nearly impossible to find. They are no longer available through HP and I've ben unable to locate one through a reseller.

Green light flashes 5 and then red light flashes 6

it's a power failure.try to replace the regulator in power supply board.

switch off .. unplug .. remove HDD .. wait a few minutes .. replace HDD .. change power cable .. try again .. if this doesn't fix it then u gotta contact Sony 08705 99 88 77 .. hope it's still under warranty or it may cost ya ..

same thing happened to me yesterday .. going to try the above fix

If you haven't done so, replace lamp part#XL2000U

Perform a partial reset of the HP All-in-One

1. Turn on the HP All-in-One.
2. Disconnect the power cord from the back of the unit.
3. Press and hold the # and 3 buttons simultaneously.
4. While still holding down the # and 3 buttons, connect the power cord to the back of the unit.
5. Continue holding the buttons until the Power button blinks.
6. Follow the instructions that display on the unit to select the language settings.

If I could be of further assistance, let me know. If this helps or solves the issue, please rate it.
Thanks, Joe

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_8b8c2cd6ce148309

The same thing has happened to me. What I ended up doing was unplugging it from the wall outlet for a few seconds and then I plugged it back in. So far, it hasn't happened again.

Unfortunately I can promise you that you CANNOT repair this. Your power and opc lights coming on, but the tv is not coming on. That is a issue within the tv. Give sharp a call and they will have somebody come fix your tv free of charge, if they cant fix it, they will replace it for free. That is the only thing you can do. Sorry bro

get a new TV :)