The screen goes complete blank with sound still on. It takes to shut TV off and power it on right away to get picture back-though the intervals getting shorter down the road . MY Screen goes black and I have full sound and can change channels

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Common LG LCD TV REPAIR - NO PICTURE OR BLACK SCREEN FIX ... I have a LG 42PM4700-UB plasma tv that justwent black. The red ... I had to keep turning on and off the TVseveral times for the screen to come back.

LCD & LED TV Repair - No Image & Blank Black Screen ...

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LED & LCD TV How to Diagnose Symptom of No Image on theScreen CLICK ... Tv was working fine when left to go to store and came back to blank picture and ... my samsung tv it turns on but its completely black and no sound at all ... LG LCD TV REPAIR - NO PICTURE SCREEN FIX REVIEW - Duration: ...

LG LED TV has no picture (black screen) but still sound ...

If you are using a hdmi cable take it off and switch to component cables if the problem goes away keep it that way. Sometimes the hdmi hookups have bugs like this.

Unplug it from power completely. Wait 15 minutes and plug it back in. If it still does it, you'll probably have to have the power supply replaced.

REPLACE THE LAMP IT IS LOCATED IN THE BACK OF THE TV THERE ARE INSTRUCTIONS IN THE OWNERS MANUAL FOR REPLACEMENT IT IS CONSIDERED CUSTOMER REPLACEABLE ITEM.
PART NUMBER 915B403001 Lamp (180W)

It seems that your unit has some sort of PSU fault, or a problem that is shutting down the Power Supply Unit, PSU. This happens so that no further damage, and possible fire will occur.

You need to take the unit to a reputable service centre/man and ask for a firm "Quote" for the work to be done. It is that re-starting that gives it away, this is a typical switchmode Power Supply problem.

When picture goes away do you see the screen still emitting light or does it go completely blank?

Depending on the answer there are two possiblities:

if the screen goes completely blank then the problem is likely in the TV's inverter and more specifically very likely in some of the high-frequency transformers. Best solution there is replacement.
Unfortunately inverters are often on one board with power in smaller TVs.

if the screen is still emitting light albiet being blank then the problem is more likely in the main board and, less often, in a cable.

Main boards often overheat and ICs relying on soldering contact bonds of 1/10 sq.mm. start misbehaving in all kinds of ways , including like you describe.

There's no simple cure for that problem - usually it's cheaper to replace the whole board or even the whole TV than to troubleshoot it.

Perhaps not great news, but that's what I know about it.

Good luck!
Bobby
http://www.coppelltvrepair.com

Hi,
This is symptom of defective red picture tube in TV that needs to be replaced.
Let me know if you want to replace it by yourself to provide you part number info or call tv tech to do the job.
Thanks.

Sounds like the CRTs are going into protective blanking due to the vertical output ic needing to be resolderd. Try resoldering the vertical IC that may possibly fix the issue.

What type of TV is this unit? An LCD or Plasma?

If it's an LCD, take a close look at the screen with a Flashlight and see if you can see some sort of picture (Almost like a ghost of an image). If this is the case, the backlight has failed.

If it's a plasma unit, you're probably looking at a power supply issue to the panel.