Difference between revisions of "Problem with red tinted display"

From ThinkWiki
Jump to: navigation, search
(Removed "cathode ray", added inverter replacement.)
Line 19: Line 19:
 
You can have IBM fix the problem if your ThinkPad is still in warranty.
 
You can have IBM fix the problem if your ThinkPad is still in warranty.
 
Or:
 
Or:
Change the Cathode ray tube, which has deceased. The phosporous layer of cold tube has a high spectrum in red, with the other spectra joining in after a few seconds, resulting in white color. this usually happens with aged tubes.
+
Change the fluorescent backlight, which has deceased. The phosporous layer of cold tube has a high spectrum in red, with the other spectra joining in after a few seconds, resulting in white color. this usually happens with aged tubes.
The tube is 2mm by 20mm and is a special part that can be ordered.
+
The tube is different sizes in different models. It can be ordered from some supply stores, but not from IBM or Lenovo.
 +
 
 +
The problem can also be caused by a bad power inverter. The inverter converts the low-voltage DC electricity from the battery to high-voltage AC to drive the fluorescent tube. The inverter failure is often a cause of the red tint in the 600 series ThinkPads. The inverter can commonly be purchased cheaply and is much quicker to replace than the CCFL (cold cathode fluorescent lamp).

Revision as of 23:06, 10 October 2005

Information about the problem of red tinted display corners in T23 ThinkPads.

Problem description

If your screen is developing a red tint on the bottom left and/or right corners, this is the sign of a dying LCD and it will slowly spread to the whole screen.

The red tint is strongest when the screen is first switched on and it will fade away with the time your ThinkPad is running.

Affected Models

  • ThinkPad A31p (2653-H4U and similar with high resolution displays)
  • ThinkPad T23 (with high resolution displays)

Affected Operating Systems

  • all

Status

It is not clear which component (screen/backlight/inverter) exactly is responsible for this.

Solutions

You can have IBM fix the problem if your ThinkPad is still in warranty. Or: Change the fluorescent backlight, which has deceased. The phosporous layer of cold tube has a high spectrum in red, with the other spectra joining in after a few seconds, resulting in white color. this usually happens with aged tubes. The tube is different sizes in different models. It can be ordered from some supply stores, but not from IBM or Lenovo.

The problem can also be caused by a bad power inverter. The inverter converts the low-voltage DC electricity from the battery to high-voltage AC to drive the fluorescent tube. The inverter failure is often a cause of the red tint in the 600 series ThinkPads. The inverter can commonly be purchased cheaply and is much quicker to replace than the CCFL (cold cathode fluorescent lamp).