CF-29 LCD / Touchscreen

I have a customer with a touchscreen on his CF-29 that appears to be going a little dimmer on the left side. Not dim enought not to see... But just dim enough to notice a difference between the left and right side. He says that it gets better as it warms up... I assumed it might be the backlight but I have never seen one fail half at a time. He sent me a picture I will try to post later.

Any ideas?

 

I've had other computers that have done this. This is not unique to the CF-29's, but is rather common in mercury based lighting systems even home fluorescent lighting.

For a little background info, mercury is used as a catalyst for the phosphorescent coating of the Backlighting of CF-29 and most household fluorescent lighting. This is accomplished by running a constant voltage potential through mercury atoms which excite the mercury electron in to a higher energy state. As the mercury electrons in the higher energy state fall back to its normal state UV radiation is emitted. The UV radiation from the mercury atoms in turn excite the electrons of the phosphorescent coating, and as these electrons fall to its normal state photons in the form of visible light is emitted.

Still following???

Okay, the reason why there is uneven lighting in your situations can be a variety of reasons, but the most common is not having a constant voltage potential (normally bad electrodes in the lighting element itself in the case of the laptop backlighting). As the computer "warms up" what is occurring may be energy distribution between good electrodes are compensating for the bad ones. There is no fix for this backlighting issue. This is also a sign that the screen is about to go. These types of screens are only meant to last 5-7 years.

To keep your screens lasting longer turn down the brightness. If there is anyone who needs to run their Toughbook’s at 1000+nit to see what’s on the screen in the comforts of their home should see a doctor immediately.


Most computer maufactures are moving away from this type of backlighting and are now using LED's. Panasonic most likely uses this because you can yield very high NIT.

 

Great explanation, Thanks

 

Well... CF-29s only have 500 nit brightness but I get what you say... On the CF-29s... I normally keep it between just under full during the day... To way down low at night when loading programs.

Like I said... I've never seen a backlight fail this way... It's usually an all or nothing... And I've seen hundreds of these things.

 

I have not noticed this before
Any sign of red/pink when booting (thats the sign of a display failing)

I have seen cf-29's for sale with close to 20,000 hrs on them with working displays

Alex

 

No red or pink.... I'm thinking inverter possibly starting to go bad.

 

This might actually be your 1st screen going bad in a "Normal" way, if you know what I mean.....

The newer models coming out from Panny will be LED. That is going to be nice, it sure will help out on the battery side. Heck, in a few more years everything will be LED in our world.

I have started to notice something a little wierd on one of my 30's. Sometimes when I boot it up, at the very top, just under the left, black antenna nub there is a flash of red, green dots for a second or two. You have to relly look for it to see it. Still under warranty! Just curious if it is a possible problem coming on.

Sometimes on my MK3 the 1000 Nit is still not bright enough. I guess what I mean is I could still use more brightness. Mostly during the day in the car though.