M1710 and E1705 no display when Touchpad is plugged in.

Hi guys,

So the story is, I've got two seemingly working Dells here with exactly the same issue. It's really strange. I've never seen anything like it. For whatever reason, they do not show any display on the internal monitor when the touchpad embedded on the palmrest assembly is connected. They do however show a picture on an external display when the touchpad is plugged in. Both of them do it.

If I however disconnect the touchpad on either, they boot as normal and show picture on the screen. If the touchpad is connected, only using an external monitor will get the display up. I've gone through 2 motherboards on each and both have the same issue. If I "hotswap" the touchpad during a diagnostics test, the touchpad actually works and moves the cursor around. XPS logo lights up on the m1710 as well.

I've tried flashing the BIOS on both and that did nothing. I just fail to see what the issue is. The cables are plugged in as far as they'll go. I don't see any loose connections on the underside either.

 

Okay, I've discovered what the problem is.

This is actually a sign of the video card dying. I remembered something like this happened on my old m1710 and when I changed the video card, it worked as normal. I noticed mild artifacting with the 7950 when plugged into an external monitor, and I noticed severe artifacting with the x1400 when the Diagnostics Test shows the colors on the screen. With the x1400, it just fades into a white void with black dots. The 7950 had rippling artifacts down the bottom of the screen and some rainbow colored dots. I swapped the cards in both systems (Used x1400 in M1710, used 7950 in E1705) and both present the same issue.

I hope this is help to other people who have had similar issues with their 9400/M90/M6300/M1710/E1705