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I have a LG 50LN5400-UA tv and the leds will not turn on. The powersupply voltage to the leds drops to 76VDC when powered on.

I have a second powersupply that does the same. Are the powersupplies both bad or is the problem with the leds?I can power the LEDs with a seperate powersupply.

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  • LG Master
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The cost to repair is going to be close to the cost of a new TV.

Posted on Dec 02, 2019


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6ya staff

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Posted on Jan 02, 2017



  • 35 Answers

SOURCE: problem booting

The power supply is your likely culprit. You probably have a bad diode in the power supply. Even if you check the voltages and everything checks out, it still could be bad because voltage checks are done with no load on the power supply. When a diode is bad, a load on the power supply can cause shut down (had the same thing happen to my pc 2 mos ago.) Try a different supply of at least the same wattage rating. If you are still having the same problem, you could be looking at a bad system board. Hope this helps. Good luck.

Posted on Jun 28, 2007


  • 556 Answers


it was not necessry to replace so many parts if you go as per proper procedure.please proceed as 1 isolate horizontal output section from power supply & make power supply ok. 2 if it becomes ok check hor osc,driver&h/output section. 3 if it is ok connect power input to hor.section which was isolated. 4 check for loose contact or print. 5 put on tv .

Posted on Sep 22, 2007


  • 151 Answers

SOURCE: powersupply

first you switch on the supply by shorting (green and black )wire in output socket of smps.then check output voltages.If there is no voltage then check switching transistors or protection transistos that is placed on first hit sink.check primary bridge and capacitors for open.

Posted on May 24, 2008



  • 227 Answers

SOURCE: RECOR COLOR TV dead high pitch whining noise

you have a short in the horizontal ckt,look for diodes,horizontal output it might be damage or a bad cap, if not the fly-back transformer is gone.

good luck

Posted on Oct 27, 2008

Walter H Boehm

  • 998 Answers

SOURCE: will not turn on when

Green LED on back of power supply indicates it's getting power. That does not mean that it's distributing the power voltages to the computer. You could have a bad power supply or a bad motherboard. Just to make surethat nothing else is causing the problem, remove any PCI cards like modem,video card, sound card, etc... Remove the memory modules and disconnect cablesto CD/DVD drives. Look at the USB ports to see if any are damaged.

Posted on Apr 13, 2011

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