Picture not HD quality while watching HD channels

go to source on your remote then click down to the second one like HD ONE.

Your Sharp Aquos 40D78UN is a 1080P HD display, and will provide razor sharp, vibrant images if provided with an HD signal.

HD signals (those that are 720P, 1080i and 1080P) are only available from the following sources:

1) Local "off air" (antenna) HD broadcasters (providing HD content) delivered via the coaxial antenna terminals.

2) An HD source such as a stand alone Blu Ray (BD) Disk player, PlayStation 3 optical (BD) disk, HD service provided by DirecTV, Disk Network, Local CATV provider or other satellite service delievered to the TV via any of the (3) HDMI jacks or (2) Component RCA jacks (RGB). Satellite and CATV providers offer both SD and HD service. You must have HD service to watch programs in the higher quality HD format.

3) Computer signals delivered via the PC (VGA 15 pin) jack - such as movies or video in HD or Netflix HD.

It is important to note that any signal source (regardless if 720 or even 1080) that is delivered to the TV via either of the (2) "A/V" RCA jacks, will be limited to SD or 480i resolutions.

An HD picture is only possible when the source is HD, it is brought to the display over HD cables to HD capable jacks on the TV and, the display is capable of at least 720P. If any one of these variables is missing or substituted, the picture quality will be reduced significantly.

CNet has a helpful review and discussed HD signals. it is only a couple pages in length and may help you understand even better. I hope this helps and good luck! Please rate my reply - thank you.

I am assuming your set is new. Ask for it to be serviced under warranty. This sounds like your set is defective for some reason.
LCD TV sets are known for their exceptional sharpness and performance when having a good quality signal source, and especially with an HD programs.

Jerry G.

Contact Sharp to locate the nearest authorized Sharp servicer. Sharp Aquos servicers have to give Aquos TV top priority. Sharp provides very good and fast serice on these sets.

hi my name is mark, i own an aquos, the side bar are normal. not all programming is broadcast in wide screen. if you watch during primetime you will see the bars come and go depending on if the program was taped in 16:9 or 4:3 format. you will see it on commericals also. thanks for your question.

If you hooked up the satelite box to your tv Automaticly the Satelite box is the one who pick up the channels (from the satelite)
In this case your tv is acting as a monitor only. Try to connect your tv with HDMI cable or COMPONENT cable for best picture. Don't use RF antenna input to hook up your Satelite Box. Hope this Helps
J

You need to verify that you have hd service with your tv provider first. Then, you need to find out which of your channels are being broadcasted in HD because not all of them will be in HD. HD cable and satellite is not capable of broadcasting in true 1080p. Some of them have on demand services that stream 1080p movies, but thats about it. Channels can only go up to 1080i(which is still beautiful hd). Make sure your HDMI cable is version 1.3 and you should be good...good luck 2u

This is a problem with the ATSC channel's reception. Usually switching to another channel and back solves the problem.

Do the lines only appear on the Cable box input? It maybe be a problem with your cable. Try to isolate the problem.

Do you see the lines on all sources such as your DVD player as well? If you press the MENU button on the Sharp remote, do the lines go through the menu as well? If yes, it is most likely a TV problem.

A bunch of lines sounds like it is most likely a problem with the connection with the LVDS cable, if not that, then a defective main board.

There isn't really much you can do about it now.
Since the TV is less than a year old, I suggest calling Sharp to locate a local authorized service center.

I think you are right about the backlight. You need to replace the backlight tube or, if you can, replace the TV. Good Luck.