LCD Flicker Repair

From eMachines Resource Portal v3.0

Guide Information

Guide Title: Correcting LCD Backlight Flicker

Created by: Compman55

Contact: <email>compman55@aol.com</email>


Summary

Walks you through fixing the LCD flicker problem that has been reported by some users. Saves you shipping the laptop back to eMachines but it voids your warrenty!


Applies to

  • Arima: W730-K8 based laptops “Any Shadow Case”
  • eMachines: m2350, m2352, m68xx, m64xx
  • Gateway: m520, 74xx, 72xx
  • Targa: Visionary 811
  • Voodoo: Envy M:860, and many other models not listed here.


Tools Needed

  1. My LCD disassembly guide
  2. A set of small flat head screwdrivers
  3. A roll of black electric tape
  4. A hot melt glue gun (Do not use low temp glue)


Before Getting Started

Tampering with any internal components excluding, external ram slot, DVD drive, and hard drive will void your warranty. So you will be taking a moderate risk. There are ways the manufacture can identify if you have been inside. Hopefully this guide will help reduce this risk. The tools listed above are mandatory to do the procedure correctly.


Problem description and solution

The problem with this case design is that whenever the LCD lid is moved, the wires going into the inverter connector move back and fourth on their terminals. Over time this will cause them to loosen up and cause the backlight to flicker. There is a permanent solution but it will require a design modification to the wiring harness allowing a different part of it to flex. You will need to disassemble the connector, pinch the terminals tighter and reinsert them back into the connector. Then to keep them from loosening again, you must glue to harness to the LCD bezel. Follow the steps below.


Procedure

Figure 1: Remove the ground tape from the inverter and the left wiring harness. Pull the right side of the inverter out first and then slide it out of the LCD bezel. Then carefully disconnect both wires from the inverter.
Figure 2: Next remove the tape from the heat sink and unplug the connector from the motherboard. Attempt to remove the ground screw going into the heat sink hold-down post. If it spins the entire post, make sure the entire harness is free, and rotate the entire harness with the screw. This will prevent twisting the wires inside. Once you have the harness removed, take the harness to a well lit area to begin the disassembly of the connector(s).

I do not have a close-up of the harness, but on each end there is a white connector block housing the wires. You will also notice there are small white fingers locking the wires into the block, thus preventing the wires from sliding out. Before you begin, mark the order of the colored wires and how they go back into the connector block. Using the smallest flat head screwdriver, bend each finger upwards allowing the wires to slide out. After you get all the wires out, gently pinch each one with a pair of needle nose pliers until the gap is exactly half of what it was before. DO NOT PINCH THEM COMPLETELY SHUT!!

At this point, you need to insert them back into the connector block and make 100% sure they are in the correct order, and that they are not in backwards. Then take your screwdriver and press the fingers firmly into the block so they hold the wires tight. Give a gentle pull to make sure the wires are secure. You may choose to do this to both connectors on the harness, even though the one for the inverter is the one that will loosen, it cannot hurt to do both. Just do one at a time so you don’t get anything mixed up.

Figure 3: Before installing the wiring harness look at this photo, tightly wrap the exposed area of the harness with the black electric tape from the end of the heat sink tape just to the point where it enters the LCD bezel. This will prevent the wires from rubbing thru on the hinge or the sharp metal plate. Reinstall the harness just like you took it out, making sure to install the motherboard side first so that you can rotate the harness with the ground screw. Then before putting the tape back on the heat sink, pull as much slack out of the wire so more is available at the hinge area.

Next, plug in both wires to the inverter and make sure none of the wires pop out of the connector block, and then finally reinstall the inverter. Now you will need to “hot glue” the harness firmly in place in the areas circled in red. Keep in mind the LCD frame still needs room to go on, so do not build up too much glue in that area, otherwise the frame will be a nightmare to assemble.

After the glue dries, move the LCD back and fourth several times. Verify the wires twist only in the hinge area. This will prevent them from loosening up again, and thus preventing the LCD flicker from coming back. I chose hot melt glue due to the fact that if necessary, it can be removed with moderate effort.


Conclusion

This guide was designed for correcting the dreaded LCD flicker that the manufacture has no fix for. For those who had the courage and basic “know how” to do this procedure, I hope this guide helped overcome some the initial fear and “cloud points” you may have had. Good Luck, and as always, your feedback is always appreciated.