Quality issues with VGA port on Type 2504 docking station

Question

Hi,
I see quality issues on the VGA output of the Type 2504 docking station with a T61. The monitor image is blurred, not much, but enough to be irritating. When I compare the DVI output with the VGA output on two equal NEC MultiSync LCD 2170NX monitors it is a clear difference. If I connect the LCD monitor to the VGA output of the T61 itself, the picture is clean. I have tried both monitors with different cables in different configurations and also adjusted monitors manually, and my conclusion is that it must be the VGA output of the 2504 that generates the un-sharpness. I have got several 2504 docking stations from the IT department to test and all attempts show the same unsharp picture on the LCD connected to the VGA port of any 2504. Recently a colleague got a new laptop and docking station. He also used DVI and VGA on the old setup and had no visible difference between the two monitors. His new setup is a different T but his new dock is also a 2504. Now he has clear difference between his monitors. He also tried several 2540 docks and cables but the difference is still present.
The unsharpness is not immediately present when just looking at a dual head setup. But after a while it becomes tiresome to look at text, specially black on white, on the monitor connected to the VGA port. There is a slight shadow on the right side of all letters. When looking at non-aliased fonts, they look as if aliased on the VGA connected monitor. Already aliased fonts tend to "smear" and I have the unpleasant feeling that my eyes are not focusing correctly.
My question is: Is there a different VGA DAC on the docking station, or are the analog signals just wired through from the laptop VGA DAC? Older IBM docks do not have this problem, we have a lot of them at work in dual head configuration with DVI + VGA to compare, and we only see this problem with the 2504.

Answer 1

VGA is an analogue signal... so it can be affected by the quality of DAC chip used by the GPU associated electronics, the quality of connectors on the vga out and dock (that is why good analgoue audio equipment use gold plated stuffs) and the quality of copper wire and shiedling used in the cable (i.e. Low Oxygen Content Copper wire).
The above is general description for all people to use <---- so please don't feel offended if i repeat something that is already said. 
There is NO conversion electronics on the dock per se, they are just passthrough, so no conversion.
I guess the problem lies with improper shielding somewhere. I have the same problem with my T61/60 and dock and my T40,41,42,43 on five different docks. 
So i have ended up using lenovo usb2dvi converter on T61 and have two dvi output and bypassed the vga altogether. 
Regards,
Jin Li
May this year, be the year of 'DO'!
I am a volunteer, and not a paid staff of Lenovo or Microsoft