How to | Board Swapping

BOARD SWAPPING is one of the easiest TV repair techniques, but one should be well-informed when going in to ensure safety and efficiency. Herein I will outline my general procedure when doing a board swap to be certain that things go as smoothly as possible. 

WARNING: Advice and instruction on this blog is to be used at your own risk. That is, you should understand that TV's operate using high voltages and can be dangerous to work with. As part of your preparations, you should unplug the set and let it have enough time to discharge (at least 15 minutes). If you are not comfortable with the repair or feel that you are not qualified to be nosing around inside the TV, DO NOT proceed. Seek professional service. The few dollars you save by doing it yourself are not worth risking your life.

1) Prepare a flat surface with something soft (towel, carpet scraps, etc.) that will not cause damage to your LCD or PDP panel. In my shop, I have a carpeted rolling bench for servicing TV's up to 60".

My work bench in my electronics shop.

2) Lay the TV down on it's face carefully, with the base stand (if attached) hanging off of the edge. You may wish to grab a friend when dealing with larger units or plasma displays (which tend to be a bit on the heavy side). 

Lay the TV face down on the prepared surface.

Pro-tip! I don't know about you, but I eat a lot of eggs because they are cheap, tasty and good for you. Even if you don't eat a lot of eggs, you can at least get through eighteen (18) of them in a reasonable amount of time. I use the egg cartons to hold my screws, usually cutting the cups into sections of six (6). It's great for keeping things organized! I've had a lot of experience with TV's and know which screws are used for what just by looking at them, but you may find it helpful to label where things go on a separate sheet of paper. 

Egg carton with labels.

3) Figure out how the base stand is attached and remove it. This LG has four (4) screws that hold the base stand on and then it slides right out.

Removing the base stand screws.

Base stand slides out.

4) Carefully remove all of the screws from the back cover, noting what type they are and where they go. You may have to remove a 1/2" nut around the coax connection on some sets, and keep in mind that there are other special cases as well. This LG is pretty cut and dry, but it doesn't hurt to have an assortment of tools or a multi-tip screwdriver and a set of bits. It's come in handy more than once for me, and was fairly inexpensive. You don't need Snap-On tools when you're working with electronics.

*NOTE* Do NOT use power tools when working with electronics. You will strip screws and break plastic components. If you are especially unlucky, you'll end up destroying traces on a circuit board, which kind of defeats the purpose of you repairing the TV in the first place!

5) Gently pry up and remove the back cover, taking care not to snap plastic tabs or otherwise damage the cover. Go slowly, it's easy to miss screws! 

Lift up the cover. Don't break anything!

6) Now that we're inside the TV, locate the part you wish you replace. Today, I'm doing a PSU swap, but as you can see, the MAIN BOARD (the one with all the inputs on it) would be a bit more of a pain to get to. If there are extra covers/brackets/etc. all you have to do is take it slow and steady and if you are not confident that you can remember how it goes back together, get out your cell phone and snap a quick photo or two.

The PSU is on the left side, and the MAIN PCB is under the metal cover on the right.

Today, I'm removing the PSU.

7) Remove all of the connected harnesses from the board headers, taking care to realize how each one works. This red power plug uses the locking tab style mechanism, and requires a small squeeze and then can be lifted out. Others have no tabs and can simply be grasped firmly and pulled from the board. Be careful not to bend pins or break headers.

The red harness is plugged into a 2-pin header on the PSU.

Squeezing the tab.

And it pops right off.

Notice the difference between the top (tab-less) and bottom (with tab) harnesses.

Without a tab to depress, just grip this firmly...

...and pop it out!

8) Take out the screws holding the board down and gently lift it from it's mounting location. 

Remove the screws holding the board in place.

Once all fasteners and cables are removed, lift out the board.

The board is removed!

9) Congratulations! You're halfway there! All you have to do now, is go in reverse. I'll let you go ahead and finish up on your own. Go slow and don't forget any screws! If something in this tutorial is unclear or you need help with a specific situation, please contact me. I'm here to help. Good luck on your future repairs!