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Eng. Andres
Eng. Andres, Engineer
Category: Electronics
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Experience:  Electronic Eng. Electronics Specialist. Circuit designer
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philips tv model 42pfl76620/12 we have sound but no pictur

Customer Question

philips tv model 42pfl76620/12 we have sound but no picture
Submitted: 4 years ago.
Category: Electronics
Expert:  TV-Tech1 replied 4 years ago.

Hello, I'm TV Tech1 and I'll be working with you to identify and help you resolve your problem.

 

There is a master / slave inverter board that is supposed to light up the lamps in the display panel. If those are bad, your display stays pitch black instead of glowing a light gray color when you press the TV's power button. They usually energize about 2-3 seconds after you press the power button.

 

Are you seeing a light gray screen on your TV set?

 

This is what your inverter boards look like on your TV, they're usually on the left and right edge of the LCD chassis --

 

graphic

 

 

Customer: replied 4 years ago.

tv making a noise now

Expert:  TV-Tech1 replied 4 years ago.

Does your screen light up, even for a second, or does it stay black all the time? It is possible that noise you hear could be the inverters whistling which would be a short noise that stops, then restarts possibly 2 or 3 times before the TV shuts itself off.

 

If that noise continues longer than that, see if it's coming from your TV speakers. Your TV could be staying turned on and just delivering sound/noise to the speakers.

 

The key is seeing if the screen lights or it doesn't.

 

Customer: replied 4 years ago.

black screen noise gone

Customer: replied 4 years ago.

screen black no noise

Expert:  TV-Tech1 replied 4 years ago.

Ok, go to the inverter board on the left side of your TV set. You should see these cables going to it. Use your voltmeter set to DC volts and measure these voltages when you turn on your TV set. If you don't have them, your backlight inverter won't turn on and the LCD panel won't light up.

 

graphic

Customer: replied 4 years ago.

i dont understand what you are saying as it is to tecnical for me

Expert:  TV-Tech1 replied 4 years ago.

Ok, you have the TV's rear cover off when you "put new fuse in tv" correct?

 

Here is a picture of the "basics" needed to test the TV set. Read all of it first. Have you checked voltages on a car before and used a voltmeter to check them?