Just got the proscan 42LA45H lcd/tv from sears set it up with the 5 cables for the dvd to work for 1080p but the tv is still at 480 what can i do ?

looks like you have a "clean all" selection in the menu under PARENTAL. See pages 15-17 of owners manual, the clear all funtion is explained at the top of page 17
(5) CLEAN ALL

SEE WEB SITE:
http://www.searspartsdirect.com/partsdirect/user-manuals/42la45h-proscan-parts-lcd+television-manual

The power supply is the most likliest cause of the issue. You can get replacement power supply from www.tvcircuitboards.com

just look at the owners manual of how to adjust the picture

Dead batteries in the remote ? Is it a universal remote correct component selected ? Will the set turn on at the TV power button ? Hard to say with such a vague description. These should give you more information to interject.

Must return for waranty repair ur main video board backlight is dead,the main video board no good.

Depends on how many things you are trying to hook up but if you are going from cable box or dvd player to your tv all you need is the HDMI in most cases as this will carry the audio and the video over the HDMI cable. You may have to double check/adjust the settings on your tv and/or the cable box/dvd player.
Thank you,
Lee

No one that I know of broadcast in 1080p yet. Only Blue-Ray DVD's. The set can't produce what's not there.

I think you have to change the settings in your HD box. Look on the diplay window of your HD box, if it says 480 there, thats where you need to change it so it will change then on your TV.

Try shopjimmy.com ,Good Luck

Here's the link to all Proscan TV Manuals =>

http://oncorpus.com/down/down.htm

Here's the link to your Proscan model#42LA45H 42" lcd tv =>

http://www.oncorpus.com/down/ENG/42LA45H%20English%20UM.pdf