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Experience:  30 Years experience. Authorized Warranty servicer.
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My LCD TV LN40A550P3F wont turn on. Screen stays black, power

Resolved Question:

My LCD TV LN40A550P3F won't turn on. Screen stays black, power indicator light blinks. No computer hooked up to it. Pushing power button won't make it turn off (stop blinking.)
Submitted: 5 years ago.
Category: TV
Expert:  TV Tech1 replied 5 years ago.

There's a KEY thing you have to look at when you TURN ON your TV set....


Does the LCD panel PRIME or not?


Priming is simply the lamps inside your TV lighting up. When your press your TV's power button the Lamps light up and you can see the TV screen go from a totally black, to a subtle gray color.


You can also verify this 100% by removing the rear cover and looking at the cutouts on the back of the LCD panel. You see white light coming out of the cutouts.


Now, there are 3 possibilities that we see --


1] Panel never lights - Inverters are bad

2] Panel lights, and stays lit -- Main video board bad

3] Panel lights, and goes out -- LCD panel is bad


So, which one do you see on your TV set?


1 and 2 are repairable....3 is expensive.


And, if you're pushing the power button too can't turn it off or on.

I wait about a minute so the TV isn't busy trying to turn the TV on.


If it doesn't allow you to turn it off or on within 3 - 5 minutes...then the micro is locked.

Could simply be caused by the type of shutdown that occurs.


Check it and get back with me.


If you have any questions, just ask

If you are finished, please press the ACCEPT button.

Tips are greatly appreciated !


Thank you.

Customer: replied 5 years ago.

I have to press the on button (on the tv itself) several times to get it to take. Then the power light comes on, but the TV doesn't, and no light from the cutouts.
If I get the power light to start blinking, it seems it does eventually (after blinking for about 10-15 minutes) turn on. Then the TV works until I turn it off. But the remote control doesn't work -- the cable box stuff does, obviously, but the volume and mute (and off) don't work.

Expert:  TV Tech1 replied 5 years ago.

I'm pretty sure you have "Bulged Caps" on your Power supply board causing that.


Can your Solder, or do you prefer to replace the board for $87.00?

I got mine in 3 days.


If you prefer board replacement, we need you to look at the right side of your TV cabinet for a sticker, and get the VERSION number off of it to get the correct part number. Here is a picture of the sticker to look at --




Let me know your choice.



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