Techmut

A generic USB-VGA adaptor is about £60 (US$100) Alternatively, what I've found is that any powered VGA splitter or booster device works perfectly, so for a cheap solution, try something like this: BELKIN OMNIVIEW VGA SIGNAL BOOSTER UK*::*Audio/Visual Cables*::*Cables*::*Custom computer, custom built pc, computer components, computer parts, CISS Ink System, Continuous Ink Systems for £38 (US$56) We have over 50 teacher laptops, which all work fine in every room, except for the Dell D505s in specific rooms. These particular rooms have die-cast aluminum boxes with a VGA extensions cable fixed into it. The other rooms, which all work fine with the D505s, have a VGA D-Sub socket mounted on a faceplate, with a soldered cable to the projector. Eliminating the room's built-in VGA extension cable by connecting the laptop directly to the projector works fine. ALL laptops in the school are set to 1024x768 @ 32bit 70Hz, so it is NOT a refresh rate/resolution issue. We do also have some Dell laptops with VGA ports which don't make proper contact with the motherboard. These have now mostly been fixed, by stripping the laptop down and pushing the VGA port pins back down onto the PCB with a hot soldering iron. (Don't use any solder on the iron, otherwise it will bridge across pins shorting them out, which is very difficult to remove)

We have exactly the same problem with some of our Dell D505 laptops, and what we have found is: When the VGA is plugged into a socket mounted in a METAL box, we get no signal; When it's plugged into a socket with just a metal faceplate, or a plastic box, it works fine. It only seems to affect the D505s, not the D510s. The only conclusion I can draw from this, is that the VGA output is too weak to travel down the extension to the projector, because of the extra signal attenuation or interference caused by the metal box. Why should it make a difference? Who knows, but it does. Solutions: a) Use a VGA extender ("booster") or splitter box b) Rewire the projector's extension socket into a plastic box c) Change the laptop for something different.