Monday, August 29, 2016

I have removed a squashed dead bug from my LCD monitor.

I successfully removed a dead squashed bug from my Dell U2412M monitor. Since I believe the internal structure of many LCD monitors are more or less the same, I am writing this post in case other people in similar situation want to know how to remove the dead bug.

How I got the dead bug

A couple of months ago,  I saw a small dot-like thing was moving on my computer monitor, Dell U2412M. I squashed it, but I could not find the carcass of the bug. I figured out that the bug was NOT on the surface of the monitor, but was inside of the monitor, because there was a dark spot where I squashed the bug. Scrubbing the surface could not remove the spot.

I searched the web and found that many people have found bugs (either dead or alive) inside their monitor. Some were stuck with the dead bug permanently lodged in their screen. I read the comments and replies, but all of them were saying "You are out of luck. There is no way to remove it."

So, I was living with the dead bug permanently at the right centre of my screen. It was not always obvious, especially when the screen is not bright, but it kept *bugging* me. I was thinking about selling it at a cheap price. How much could I get by selling this monitor? If I lucky, perhaps $100?

Preparation

After it living the dead bug for months, I decided to take the risk. I had no previous experience of opening computer monitors at all. I could destroy the monitor completely. Currently, at least I can use the monitor, albeit the dead bug is bugging me. But then I thought it could be just $100 loss if I destroy it. Well, life is full of tough choices, isn't it?

I searched the web again for the internal structure of LCD monitors and panels. Fortunately, my model U2412M is a quite popular model worldwide. I could find a "de-bezel" video of this model on YouTube. From that video, I learned how to take of the bezel and the back plastic casing. Then I watched quite a lot of LCD panel disassembly videos on YouTube. Basically it is a few layers of panels inside a flat rectangle metal casing. At the front there is the glass LCD panel. Beneath that are the plastic films for defusing the backlight. Beneath that is the back-light glass panel.

Execution


Today, I finally tried to remove the bug. Opening the bezel was relatively easy. It did not need any tool. There were many latches, and I broke only one of them. Removing the back plastic casing was also very easy. All I had to take a caution about was removing the cable that connected the control panel and the USB port at the side of the monitor.

Now, the hard part: opening the metal casing of the LCD panel. There were 4 small screws at the back of the LCD panel. And the a long thin panel at the back of it, could be easily removed by removing the 3 small screws. Yet the problem was the latches all around the metal casing. There was no video explaining how to remove it. A web site description said that latches can be easily opened by prying it with a flat screw driver. But I was worried about damaging the glass LCD panel. I wasted a lot of time (1 hour?) on this. Finally, I pried open all  latches by inserting the flat screw driver from behind of the latches.

The bottom side of the glass LCD panel was connected to the backlight module, but other sides (top, left, right) were not connected to anything at all. So I could just lift the glass panel from the top without disconnecting anything. As I suspected, beneath the glass LCD panel and the plastic diffuser film, was the dead, squashed bug. You imbecile! Of all the place you could go, why did you go there? Anyways, I removed the squashed carcass of the bug. But while doing so, many small dusts got into it. I think I could have removed many of the dusts if there was another person who was holding the LCD panel compartment bottom side up. That way, the dusts could have fallen into the floor. But since I worked alone, I laid the LCD compartment on the floor. The fallen dusts stayed on the diffuser film. I removed as much dusts I can with my hand, but it was almost impossible to remove them all.

See the cross-section of Dell U2412M below (the terms may not be correct, because I just named them). In short,

  1. Remove the bezel (black)
  2. Remove the rear case (sky blue)
  3. Remove the panel compartment front casing (purple)
  4. Lift the glass LCD panel (green)
  5. Remove the bug





Result

Fortunately, those many small dusts seem to have little effect on the actual screen. I put everything together and cleaned the outer surface. I did not measure the total elapsed time, but I guess it might have taken about 3 hours. Now the dead bug is gone and I can hardly see any dusts. There is a small faint one around the left bottom of the screen, which I cannot remember if it was there before or added today. But it is far better than having a dead bug at the centre of the screen. And if I really do not like it, I think I can open the monitor again and clean it. This time it would take about 1 hour.

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