04-29-2012 05:07 AM
I had my first white blob (middle right of display) within a few months of getting my T420s. I was annoyed but assumed that someone else had over-enthusiastically poked the screen with a finger or pen.
Then another, lesser, white blob, appeared in the middle left of the display. Now I can see some lesser white blobs working their way up the display from the middle right blob. It may be significant that the blobs are almost in line with the rubber pads at the top of the display. Maybe I'm imagining thigs but the camera also seems to have picked up a row across the middle.
I've never had anything similar with the many other notebooks I have owned in the past 25 years and have to consider it to be a defect with either the panel or the display back putting unplanned pressure on the back of the panel (LG LP140WD2-TLB1). Hence, it looks to be to be a latent defect with either the design or the materials and would like Lenovo to confirm this to be the case before I get into an argument with the UK service people.
04-29-2012 07:42 AM
04-29-2012 12:17 PM
By my measurements the white blob on the right is 10cm down from the top edge of the lid. Measuring 10cm in from the front of the notebook puts the white blob on the right hand Ctrl key. the less white blobs above it would be against the palm rest.
04-30-2012 10:55 AM - edited 04-30-2012 10:56 AM
If these do line up with keys, then perhaps it suggests that service could be right that this could be pressure induced and not just naturally occuring. Now, how that happened is difficult to say without seeing your system.
Is it possibly out of spec and allowing the screen to rest on the keys? Is it being carried with another item, like a porfolio or notebook (as I'm prone to do) and clamped under arm or in hand as you walk around? Or perhaps carried in a case along with other books or materials? Any of these situations could press the screen into the keys.
Again, difficult to say for certain without seeing the system and inspecting space between LCD and keys when closed or to know anything about how it is transported. Hopefully things work out in your favor with service - please do keep us posted on what they say.
Could you send me a PM with your case number, system model and serial and your contact details? We can look into this further.
05-04-2012 01:38 AM
@Mark: My T420s has been carried in the same bag as the Dell E6400 and E6410 that I used previously but, since the T420s is thinner then it should be getting less external pressure.
I don't buy into the hypothesis that the white spots are caused by the display being pressed against the keyboard. That problem would leave visible marks on the surface of the display (a problem I had with the Dell E6400). I therefore believe that the problem is more likely to be caused by the LCD rear cover pushing against the back of the display, which would suggest that the rear cover is not doing its job properly. I'm particularly intrigued that the broad pattern of my white spots matches the reversed L feature in the rear cover as shown on the illustrations in the Hardware Maintenance Manual.
Please review your comments in the light of my additional observations.
05-05-2012 06:01 PM
05-06-2012 12:16 AM - edited 05-06-2012 12:18 AM
My T420s developed 5 white spots on its LG Phillips display after about 1 year of usage. Got it replaced under waranty (3 years NBD ThinkPlus) after a single phone call to local service center (in Czech republic). One white spot was above palmrest, so definitely no keyboard pressure.
Got AUO panel this time (B140RW02 V1). After some adjustments it looks pretty good.
05-08-2012 08:44 AM - edited 05-08-2012 10:11 AM
Thanks for the additional insight. We will continue to look into this - that is a good theory you have proposed.
I've looked at some of the pics on NBR and looked over the threads and I'm interested, but don't think we have a clear picuture other than some people have white spots on the display. Some seem to have a pattern like yours, and then some seem to be a single spot rather than a pattern. There doesn't seem to be any consenensus about a particular LCD manufacturer.
While we can try to bring in another system in Europe, it may also be faster if anyone in the US has a T420s exhibiting this that they would be willing to let us have a look at.
06-05-2012 10:58 PM
I understand the frustration and sorry for the delay in reply. As the engineering side has looked into the issue am currently dicussing the next course of action. I understand this has taken alot of your time but rest assure that we'll keep you posted as soon as we can get update.