LG OLED TV 77 inch SMPS Board Replacement

Written By: bseagrave
  • Comments: 4
LG OLED TV 77 inch SMPS Board Replacement

Difficulty

Moderate

Steps

7

Time Required

30 minutes

Introduction

Resolves screen not coming on — On attempt to turn on TV one hears the customary power-on click but red standby light remains lit (does not flash) and screen remains off.

    • Make sure there is nothing on the clean surface that can scratch the screen. Two people are required to gently lay TV face down.

    • Remove tiny black phillips screws. Two are in the bottom of TV, one on each end. Two are behind a small removable panel in the center back. One is where the power cord goes into back of TV.

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    • Use a strong plastic spudger to pry off the back cover. With fingertips at bottom pull the cover up from the back of the TV. Get tip of spudger under it and slide around the corner to side. Pull up with slight pressure. There are one clip on each side and 8 clips across the top. Slide the spudger around top and sides to pry loose each clip.

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    • Power cord is clipped to the back panel then connects to Power Board where shown by arrow in this photo. Pinch the clips on either side to detach cord from Power Board.

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    • There are four cable harnesses connected to the power board. In this photo the one at top (to mother board) is disconnected -- squeeze the white tabs at each end to disconnect it. Squeeze the black sides of other 3 harnesses to disconnect them. Two harnesses look identical. Mark one with a sharpie so you can distinguish it on reassembly. See arrow.

    You can see I marked the inside harness with a black sharpie. I made a note that the marked harness went in the inside socket.

    bseagrave -

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    • Remove 7 phillips screws attaching power board to TV. Replace the power board with LG OLED77C8PUA Power Supply (LGP77C8-18OP) EAY64748801. Available from Michigan Service Parts via Walmart.com

    I'm thinking of adding an active cooling system to my TV so would love it if anyone could supply photos of what the back of the TV looks like when plate is removed. (I'm disabled so would struggle with this myself.

    But my idea is too add a type of trunking along the top vent and add exhaust van along it or either end too force cool air threw the bottom to circulate.

    Any thoughts it may be a dumb idea and not worth it, but could extend the life of the TV

    Derek Pearse -

    • Be sure to hook the power cord into the back panel. This prevents it from being yanked off the board in an accident like by tripping over the cord.

    Remember to feed your cord through the cut-out in the back panel before reattaching the power cord to the board.

    bseagrave -

Conclusion

To reassemble your device, follow these instructions in reverse order.

Author

bseagrave

Member since: 23/07/11

364 Reputation

One comment

Do you know if this fixes a similar problem in which there is no picture but the standby light flashes 3 times before staying lit? Or does that need a different part replacement?

Michael -