I have a Sharp LC-20SH21U LCD TV that powers up and very briefly displays a message that says Please wait.... Then the screen goes dark for a few moments then flashes a gray screen for a moment then goes dark again permanently. The power light stays blue as long as I have the coax connected which is coming from a DVR. When I connect the DVR coax to another TV it shows a picture and has audio with no problem. Any ideas? Thanks. Mark

There should be some loose solder points at its main digital board. Check it.

Sounds like a power supply problem - take off the back check voltages coming from power supply if they are good check your inverter board to make sure they are good.

Thanks,
michael

i have the same problem. i just replace the power board because of the "green blinking" light. now, light stays green, picture comes on for a few seconds, then blank....

did you fix your problem.

My 3 year old Sharp LC-40C32U would start up fine but within a minute would go dark (audio continued fine). For a while I could turn the set off and on again and it would be fine, but over time this became less effective. My solution, which has worked for a week now, was to a) unplug the set's power cord; b) after 3 minutes plug it back in and turn the set on; c) on the remote hit MENU and slide over to SETUP (3 clicks to the right if the screen is dark) and one up to RESET; d) hit ENTER and follow the prompts. This puts the set in it's factory configuration so you will have to rescan for channels. Worked for me.

Off/On The Power switch sudden 4 Straight lines appear on the screen ! what is that & why ?

HI, you will need to replace the Digital PCB in this unit. the chip set has become unstable. there is some major circuit damage as well. AKA(PWB UNIT)


Sharp Part Number: A3Y004GDH0 $262.95

its the motherboard. i got the same tv with cracked screen. i can sell you the motherboard for cheap or i will buy your lcd to fix mines. if interested email me at [email protected]

see the link below but first make sure here is no dvd in the drive
because a bad dvd can cause this problem

working on sharp lcd tv dvd combo LC 26DV20UPLEASE WAIT

Main digital board fault. Check and replace it. Contact any service technician. If you wish to get more details visit the site linked here. http://electronicshelponline.blogspot.com/

Do you still have this, I need a part myself and having trouble sourcing parts?
Mine immediately goes into standby mode and the screen just shows a white flash. I'm sure its just a power issue.
[email protected]