Thinkpad T60: VGA output is tinted yellow (but not DVI output)

Question

I have a Thinkpad T60 that I use at work. When I plug in an external monitor to the VGA port of the machine (either the VGA port in the laptop's docking station, or the VGA port built into the laptop itself), the image on that monitor appears tinted yellow. (White appears as yellow; gray appears as light red; blue, green, and yellow are mostly unchanged.)

This behavior does not occur on an external monitor plugged in via the docking station's DVI port -- colors appear normally on an external monitor plugged in via DVI. The laptop's built-in screen also displays colors normally.

The behavior does occur with more than one specific external monitor and VGA cable. (Specifically, I see the behavior both with the VGA-cabled monitor at my desk, and also with any VGA-cabled projector that I've used with this machine.)

I've poked around in Display Properties, but so far, I haven't found any settings that appear to be causing the problem. (In particular, there are no special color profiles set up at Display Properties | Settings | Advanced | Color Management.)

I'm running Windows XP SP3. The video card in the machine is an ATI Mobility Radeon X1300. Video driver version is 8.442.3.0, dated 1/3/2008. (I'm a little leery about updating the video driver on this machine, since it's my primary work machine, and I don't really want to risk downtime as a result of doing an upgrade -- I've run into that a couple of other times on this machine when upgrading other drivers. So I haven't tried to update the video driver as a fix for this issue yet.)

So, two questions:

(1) What is the likely cause of the yellow-tinted output from the VGA port?

(2) How can I get the VGA port on this machine to output normal colors?

I can live with the issue on the external monitor at my desk, but it's a little bit embarassing/annoying when doing presentations with the machine, using a projector connected via the VGA port.

Thanks!

Solution 1

To me, that sounds like the vga port on the laptop is loose or going out. I saw this commonly happen with some T40's. That is a motherboard replacement most likely to fix it. Take advantage of your warranty if you have one. So that answers both of your questions.

The docking station port would do the same thing if the one on the laptop was giving the issue. I am sure you have made sure the cable was tight and you said you tried other cables.

Solution 2

Sounds like one of the connectors in the VGA socket may have stopped working, unfortunately if that is the case you'd need to send it back for repair.

Solution 3

The blue pin seems dead, broken or bent. Contrary to believe, this can happen with DVI too. DVI sends the different colour channels over different data pins too.

Comments

[Michael Kohne]

Unlike DVI, VGA is quite analog, so if a pin is making poor connection (either because the pin in the connector isn't in good shape, or because the connection to the motherboard is damaged), you'll get bad signals on that pin, which will screw up the output visuals. Since you've tried other cables and monitors, it's back to the service guys I'm afraid.

[underscore_d]

Not that DVI's relevant here, but it uses 2 differential pins per channel, and are we sure the receiving monitor would even accept the signal if one of those were missing? i.e. is there no CRC or other checking on it?