LCD tv screen goes dark after a few seconds of being on

No, the screen goes completely dark.  Works perfect for 5 seconds, then goes off.  Sound continues just fine.  If I turn TV off and back on, the picture comes back on... for 5 seconds, then goes off.

Then your video driver is most likly bad.  Have you tried a different input?

>> suthngin said: Then your video driver is most likly bad.  Have you tried a different input?

Different inputs make no difference.  Once it goes dark, I can flip between inputs and the screen stays dark. Not even built-in menus display.

That said, however... if I switch to another video input and wait about 20 seconds before switching back to the first video input, the screen works again for 5 seconds until blacking out again.


>> Callandor said: The circuit that drives the tv display has gone bad.  Since it's an LCD screen, this could be the inverter that drives the CCFL tubes or the display circuitry itself.

What would that mean for me if it is the inverter or the display circuitry? Any way to verify if it is either of those? Are either of those components able to be repaired/replaced by the consumer?

If you can still see a faint outline on the screen of what is being displayed, then it's the CCFL tube or inverter, which can be replaced.  If not, it's more serious and will require a TV technician or replacement.

Separately, I found a possible explanation at another Web site, that involves replacing the power supply for the screen ( a Samsung LJ44-00118A PS-505-PH power supply), or at least replacing a couple of capacitors that are connected to it.  Here's a link to the description:

http://www.fixya.com/support/t2453091-tv_goes_black

In your experience, does this sound likely?

(Previous post is only intended to explore another option other than replacing the tv!)

Thanks, all, for your thoughts.  Haven't yet taken the opportunity to open it up and take a look, but will hopefully do that soon.

I have the same problem with my Westinghouse. What was your final action on it?

UPDATE: I finally pried off the back of my Westinghouse.  I don't see anything that resembles the PCB photos that were linked from the potential solution I found at FixYa (see my link above), although I *do* readily see the inverter which Callandor mentioned could be the culprit. Printed on my inverter is "Darfon B070-601."

This is a LIPS (Line Independent Power Supply) inverter.  Information on LIPS inverters can be found here -- http://www.lcdparts.net/LIPS3D.aspx -- although this site indicates my Westinghouse SK-32H540S uses a Darfon 4H.B0700.071 inverter, which it lists as obsolete. As I mentioned, however, mine is a Darfon B070-601.

The lcdparts site notes that the symptoms of a defective inverter can include:
    *  No Power
    * Power Indicate light flash on and goes off
    * Screen Flash on and Off between 1/2 to a few seconds
    * No Display or Dim screen
    * power light cycles on and off

This *could* be my problem (4th bullet), although it's apparently a total-replacement kind of fix (around $160).

I'm hoping I might still be able to replace a capacitor or two on the Darfon inverter, just like the FixYa solution I found suggested for a defective Samsung power supply.  But the problem is that the capacitors on my Darfon don't match the capacitors described on the Samsung in the FixYa solution.  PLUS... none of my inverter's capacitors look deformed or cracked, so I can't tell which little component might be the problem.

SO... I might just have to replace the whole inverter...   :(

... unless anyone has any further suggestions?  :)

>none of my inverter's capacitors look deformed or cracked,

Mine were very slighty 'not-perfectly flat', not really noticeable until I got the new ones.

Hmmm...

But which capacitors should I be paying attention to?  The two big ones?  (In my case, they are 330uf and, I believe, 10 or 20 V, and almost the size of a standard C battery.

Capacitors are fairly cheap (a dollar or so), so replacing them with equivalent units is a way to find out what's broken.