Introduction: How to Repair Dead Mainboard on INSIGNIA LED TV NS-46e3401a13
This was down because my Insignia TV just stopped working after doing a firmware upgrade through a thumbdrive. It was completely dead. I knew I had a good power supply so I didnt have to worry about that side (board in the middle of picture). All other websites suggested to replace the Mainboard which in would have fixed it. However they discontinued making the replacement mainboard for my specific model. I researched and found that maybe by replacing just the EEPROM chip on the mainboard might bring it back which it did. Also, by replacing the EEPROM chip fixes other errors happening with the TV such as turning off suddenly or power light is ON but doesn't come on when power is pressed. That is because the EEPROM holds the basic instruction set for the TV's microprocessor and if it gets corrupted bad things start to happen...such as no response when the power button is pushed. So my only option was to buy a new TV or try this inexpensive self-repair.
This will take a little soldering skills and require:
>EEPROM replacement chip -- about 20 bucks on ebay for this model it was the U403 EEPROM chip
>soldering kit -about 10 bucks on Amazon
>small Phillips screw driver set
>small wire cutters
>I used a magnifying glass stand to help see during soldering.
>one Exacto knife -about 2 bucks
>heat sink compound to bind the heat shield to the microprocessor again. -about 3 bucks at RadioShack
Step 1: Remove the Back Cover of the Tv.
You will need a small set of Phillips screw drivers to remove the back of the tv set to expose the electronic boards. There will be two big boards...the first one is the power board in the center (brown colored circuit board). The Main Board is to the right (green colored board) and I marked where the chip is located with a small black and yellow handle screwdriver (see picture). The chip is under the silver heat sink plate. Remove the screws that hold down this mainboard and gently unsnap the wire bundles connected to the board. You should be able to lift the mainboard away from the tv. There is possibly a small sponge type cushion in the back of the board that may stick when you try to pull/lift the board away from the tv. It's okay to "unstick" it when you lift the board away.
While holding the board upside down in your hands...try to snip the legs that are holding the aluminum heat shield/sink...Next, by applying the soldering iron tip to the snipped legs and simultaneously lift each area of the heat shield away from the board until you can remove it or lift the heat shield away from the EEPROM chip enough to do your work. I gently used the small screw driver to lift away as I applied the soldering iron to to the leg areas I just snipped. The board slowly lifted each leg away as I pulled the heat shield away when doing the soldering iron.
Step 2: Removing and Soldering the New EEPROM Chip!
BEFORE YOU REMOVE THE CHIP TAKE NOTE ON HOW IT IS LAYING OR IT'S ORIENTATION BECAUSE YOU DO NOT WANT TO PUT IT IN BACKWARDS..LOOK AT WHICH SIDE IS THE WRITING ON THE CHIP AND OR THE NOTCH...THE NEW ONE HAS TO GO IN THE SAME DIRECTION!!!!
Next take the Exacto knife and cut the EEPROM chip free by cutting down through the 8 legs of the chip. Press down with the pointed tip of the knife through each leg using the side of the chip as a guide. IT DOES NOT TAKE MUCH PRESSURE TO CUT THE LEGS. Once the chip is free, clean the area of remaining cut legs and excess solder with your soldering iron and suction.
Place the new chip in the same position and lay the legs over the exact same contacts as the old chip. Next solder on the chip carefully. Your contacts may touch each other but clean them up after your solder all 8 legs. Now go back and clean up your solder for each leg and make sure there are no cross connections to other legs! (see 4th picture)
Now, screw back in mainboard to back of tv set. Reconnect your wire bundles. Apply some heat sink compound to the top of the microprocessor and lay the heat shield down and gently press to adhere. If it doesn't stay down, use a little masking tape to hold it down on the edges only! Do not cover the heat shield with masking tape!
Close the back with the cover and replace all the screws.
Step 3: Test Your Tv
when you put the TV back together. Plug it in. If all went well you should see a red power light. Press the power switch ON. Hopefully it will come up with INSIGNIA splash screen!
If it doesn't get the red power light then recheck your soldering connections. If it still doesn't work...it could be a bad power supply. That will be another whole separate issue outside this instruction. In that case, you could replace the powerboard or try looking for bad capacitors or burnt connections on the board.