BMH Online  Projects


[Back to Projects]

  Asus 550C Touchscreen...

[27 November 2020] I had an Asus 550C Touchscreen with faulty screen to fix:

Notice the purple bands running along the top and bottom

Disclaimer: This is the procedure I undertook to repair this faulty laptop. If you don't know what you're doing then don't do it! Attempting any of this could cause more damage or a more costly repair.

I wasn't certain if it was a cable fault or a screen issue; I looked online for examples but it still wasn't conclusive in this case. I opened and closed the lid to see if the movement of the cable would affect the image but it didn't.

I tried a replacement cable first, since that would be the easiest and cheapest part to replace, but it turned out to be the screen at fault.

The tools I used:
  • A screwdriver
  • A pry tool
  • A heatgun
  • Superglue

The procedure required dismantling the laptop in a typical fashion in order to remove the screen section.

It may be possible to replace the screen without unfixing it from the base of the laptop, however, there are three screws along the bottom edge of the screen, hidden under little square adhesive covers and it is unlikely that these are accessible with the screen tilted as far back as it will go. With the screen attached, the rest of the procedure would be likely more challenging.

The base section is held together with various screws but is also clipped together, so a pry tool is required. Delicate ribbon cables are in place for the power button, keyboard and mouse, so care needs to be taken when removing the keyboard layer and these cables. With that out of the way, replacing the screen cable required removing the screen section (held in with screws to each of the hinges) and with the base section disassembled the motherboard also needed removing since, while the screen socket is on the top of it, the cable folds round the edge and under the motherboard.

With the three screws removed from the bottom edge of the screen it is necessary to use a pry tool to work round the outer edge of the screen to carefully unclip it*.

The screen and webcam modules were carefully unplugged and the screen's cable carefully peeled off the back of the screen.

Since this is a touchscreen model a digitizer forms the outer screen with the actual screen is a layer beneath and held in with an adhesive strip running round the perimeter. I cleared my work area in preparation and then with access now to the back of the screen, and the screen placed face down on a soft surface, I used a heatgun to slowly warm up the back of the screen, working my way around the perimeter until the adhesive was softened just enough to pull the screen away from its housing. This is a similar technique employed when disassembling an iPad or other tablets or smartphones.

I had the replacement screen ready to one side and as soon as I was ready I pulled the old screen away and placed that to one side, and then I removed the protective film from the new screen and immediately (and carefully) lowered it into place, being sure to get the corners and "guide-pins/holes" lining up as it met with the original adhesive.

I was keen to get the replacement screen into place carefully and swiftly (holding only the very edges) to minimise the risk of anything contaminating the new screen or back of the digitizer since once back together any specs of dust (or fingerprints!) would be noticable and trapped. I also took advantage of the original adhesive tape still being warm and tacky enough to hold the new screen; I applied gentle pressure around the perimeter to ensure it was sticking and then carefully placed some large books on the back of the screen and left them there until it had all cooled down (30 minutes).

*Since I had been careful to unclip the lid plastic part of the screen I thought I could just line it up with the front bevel section and clip it back into place, and put the three screws back in with the little adhesive covers, but sadly it wouldn't clip on. It seemed the clips had been damaged or bent preventing this. I resorted to using superglue to fix the plastics back together which meant the final result wasn't perfect in appearance but it was functional and the screen itself was working properly.

I reassembled the laptop and tested it to confirm all was well (keyboard, mouse and power cables etc. all functioning).

[Back to Top]