Image on TV constantly blacks out, what is wrong with it?

Question

Lately, my TV (not a plasma, just those old heavy ones) has been acting strange.

Whenever you turn it on the images do not come up (the sound is still there though). You have to turn it off and bang the tv to death, and then it would at least work for a few seconds. It constantly blanks out--even if you try hitting it to make it work.

Sometimes I get lucky and after hitting the sides and the back, the TV will work fine, but usually, it rarely works right.

Why does the image dissapear? Is the TV busted? Is there anyway to fix it, or do you have any suggestions? Is there somethin wrong internally, and should I open it to fix/find out what the cause is?

Answer 1

When a TV set like your's blanks out, it's most likely the Vertical Deflection is failing , and to protect the picture tubes on it from burning a line into the center of the picture tube, IT BLANKS the picture !

Been there done that....

And depending on model and Brand, you could have loose solder on the Vertical output IC, the Vertical power supply circuit or the Yoke Plugs.....

That's what normally causes a picture to blank out on the OLD Heavy ones....

And then there's the 9 Volt regulator that gets bad connections.....That's another blank-generator on certain brands....

Now on smaller TVs like a 32 or 35 inch TV with a Picture tube you can touch with your hand (called Direct View CRT), on those I normally see the HORIZ drive transformer and resistor get loose connections...but those don't CHARGE UP when you turn them on either....

That's why TV Techs ask a lot of questions....Is it a CRT you can touch (Direct View) or a plastic screen on a big box. (CRT projection TV)

Do you see a thin line from left to right before it blanks? Does the top and bottom shrink at all?  (Vertical !)

Does the TV develop Hi Voltage? Can you hear it crackle when turned on?  (Horizontal)

What brand, What model?

These all help us to determine your failure.....