Just replaced power board , tv powers up, picture on tv lasts about 15 to 20 min then screen goes blank , still have sound . If i turn tv off and unplug power cord and let tv stay off for about 30 min and turn back on tv works for about same amount of time

when the TV goes dark, shine a flash light on the screen- hold it very close.
if you see a little bit of the image, your backlight has failed. That would mean you would need to replace the LCD panel.

also check the power cord wire coming from the back of the tv is loose from the tv side or perfect.

If you have electronics experience - check the power supply and make sure you are getting the correct voltage to your inverter boards and main av board - also do you see any movement on the screen take a flashlight and shine on the screen - if you can see a dark image on the screen check inverter boards and power first.

thanks,

michael

The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.
Search the site by type in the "brand name" to your device; [Exclude the model number], in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

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)

Hello,

If you turn the monitor off then about 1020 sec turn it back on and have a picture for five sec again it sound like the power supply in the monitor. but if that did not solve the problem, the picture board on your monitor is bad, since it goes off after few seconds and the power led or button is on, it means the picture board of your monitor has developed fault and will need to be replace.

I advice you replace the picture board on the screen of your monitor to solve the problem of the blank screen.

Take care.

Ur tv now power on only have picture few mins,than dead,have sound only?Yes,than the 1 or 2 the long board call the LCD inverter boards are dead.The LCD inverter long boards help the LCD screen to have a backlight to produced a picture.Tries websites like Shopjimmy.com,Ebay.com to buy 1 or 2 long LCD inverter boards for the replacement.

Ur tv LCD inverter board it dead.Replaced this LCD inverter board ur tv picture will return.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish LCD inverter board for the replacement.It a long board in shape.

helloFive blinks - AKB circuit (automatic kine bias), the timer/standby indicator blinks for about 30 seconds then goes to the self-diagnosis function. Something is wrong with the video. Check video out, Q705, 732, 761 and other components on the C board, also check Q218, 219, 220 on the A board. In addition, unit could be in IK blanking, try turning up screen slightly.

shaun

i have a secptre t v turns on for a sec and screen is blue then goes to blank screen can anyone help