We connected the computer to polaroid lcd screen and it doesnt want to turn on can any one help me

Question edited for a lot more clarity.

It depends on what comes out of the karaole machine. This with what the television will take.

TV Type LCD Screen Size Screen Definition 720p Resolution Contrast Ratio Aspect Ratio TV Features Closed Caption, DVD Player, V-Chip Video Format ATSC (Digital), NTSC (Analog) I/O Interfaces S-Video, Composite, Coaxial, RCA, Component Enclosure Color Black Accessories Stand, Remote Control
The video may help

https://www.google.com/search?q=polaroid+1521-tlub+as+karaoke+monitor

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combination of loss of your power supply and blown resistors take it to a shop

Double check your connections. General rule of thumb, if the problem changes after you are in the set, it is probably something you did.
As for your original problem, it sounds as if you either have a bad capacitor or the tcp onthe panel is going bad.

Your model is a LCD flat panel which doesnt have a lamp. Instead they have a series of flourescent tubes behind the Screen which light the screen. The backlights hardly ever fail its usually the Inverters which fail when you dont have any picture with that model. You can get the inverter board and free technical assistance from www.tvrepairworld.com

Sounds like you need a new control board. Check www.partstore.com They should have it at a good price. Let me know how this works out.

hardrocko

this might help

http://www.fixya.com/support/r741402-polaroid_flm_373b_lcd_tv_black_screen

I have a flat screen polaroid lcd hdtv model 3700, first the sound started to get really loud with a beeeeeeeeep when we turned on and after a while was gone, now it doesnt! we had to put mute and connect the tv to a sorround system to hear it without that crazy noise, and now the colors of the tv are gone too its just black and white when we try to see the dish satelite but if we put a movie on the dvd player colors are perfect we try to conect the ps3 player too but its black and white too. Help what can it be!!!!????

two options _bad backlight inverter or the main board ;eed to be change.

First check all of your connections (power as well as video connections). If they are all secure, then make sure that if there are multiple inputs that you have it on the correct input (by cycling through the sources with the corresponding button). If none of that works then look carefully at your screen to see if you can make out anything on the screen. Sometimes if the LCD inverter goes out then everything is VERY dark. Hope this helps.

There is not a good solution. If you read about the Polaroid 37" LCD HDTV, you have a problem and it's the same one that many of us have. According to Polaroid's service center, the control box needs to be replaced. Polaroid does not stand by this product. The company gives you a lot of lip service about how many they sell and how few problems they have - they're lying. The TV's should be recalled and I'd suggest you join many of us to demand it. Write BBB, write the company where you bought the TV, write any consumer group you can think of - Polaroid TV's are junk. Sorry you've got one. Sounded like a good deal and Polaroid used to manufacture quality - no more.