I have lines on the screen of my polaroid 37 inch

No Model number, '50 inch' is just a size.



Can it be fixed? Yes, they can all be fixed.

Is it worth it? Unlikely. Polaroid are a camera maker and don't have a good name in televisions.



Hopefully our television @Larry will be along to confirm.



https://www.google.com/search?q=Polaroid+TV+50%22+fault+across+bottom+of+screen%2C+transparent+band+about+2+inches+high



..

This type of issue can only be fix by a professional tech specially if its a flat screen TV. the line across indicate that there is a problem with the projection of the unit.

If you wish to get some details; visit the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

How to fix lcd lines on Sharp tv screen, hdmi video board ...

? 3:43
https://www.youtube.com/watch?v=cHki4D0EwOo
May 24, 2014 - Uploaded by Tampatec
How to fix LCD lines on Sharp TV screen, hdmi video board easy ... Make Money From Your Broken Cracked LCD LED PLASMATV ... TV Repair Help for Vertical & Horizontal Lines on Your TV Screen ... Sharp Aquos LC-32 37 46 52DH65E 66E 77E - NoPic/Sound with ... Get video URL at current time.

comments on LCD Display Symptoms and causes. - YouTube

https://www.youtube.com/all_comments?v=DedJvyNm_s4

We have frequent outages causing the TV to turn on from standby mode when power returns. (These ..... Sharp LC-70LE650U 70-Inch Aquos TV TURNS ON WITH PERFECT PICTURE AND ..... It has thin horizontal lines on the top quarter of thescreen. ..... hey there, bought a 52lg60-ua had no image/picture but had sound.

LCD Display Symptoms and causes. - YouTube

? 2:01
https://www.youtube.com/watch?v=DedJvyNm_s4

More likely to be the porblem in the T-CON board (driven by Logic bd.) or the main Logic board.
Please see my basic troubleshooting guide:
http://s807.photobucket.com/home/budm/allalbums
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://en.wikipedia.org/wiki/Capacitor_plague
Parts: try www.shopjimmy.com or Ebay

i fixed one by put 2 new caps in c112 and c113 1000uf 10v

Sounds like you need to repair the power supply, don't fret, it can be really easy.  Here is a pair of youtube videos I made after following some advice on this website from other posters:

 

http://www.youtube.com/watch?v=qSS6ycUxS98

 

http://www.youtube.com/watch?v=oTOkHKPJsnM

i think by accident you have changed the input when you went to change the volume. look for a button labeled " input" or "video" select on the remote and scroll through the various choices. you should get your picture back.

Yes it could and most likely is the power supply board. If you look at the capacitors on the board you may see some that appear swelled or puffed up at the top. If you see any that are puffed up they are leaky and replacing them may fix the problem. Some times if the Inverter board is bad it will not let the TV come on. a LED will be blinking. If you have no power at all it is most likely the power supply.