Web Camera not found (XPS M1330) - Probably cable disconnected

Step 10 under Removing the Display Assembly will show you where the camera cable is located. 

I would recommend looking at device manager first to see if there's any devices that aren't recognized, going into the computer should be your last resort since you void your warranty if the chassis is opened without a technicians presence in person or via phone. Instead, you should look at Vista, there are Automatic updates that like to overwrite the Dell drivers that were designed for your system. Run the System File Checker (to find out more google search "sfc /scannow") and Check Disk (google search CHKDSK /R) to see if windows can fid itself. It's harder than you might think to not notice a cable connection and I'd bet on the technician more than Vista any day of the week. I like you're initiative, though!

Cheers

I've got the same problem with my XPS M1330, let me share what's been done and oh by the way it's still not fixed.

1. Downloaded new WebCam Manager from Dell Support; after installing checked WebCam and it gives me the error no webcam connected. Checked Device Manager and there is no Imaging Device listed and also no errors on any devices.

2. Contacted Dell IM Support, after quite some time, tech support determined I had a bad webcam; sent out new webcam.

3. Dell support sent out technician to replace webcam; he replaced webcam and still had the same issue. Informed me it was a software problem and he only does hardware. Also stated I might as well back-up my hard drive since when I call Dell support back they'll have me reformat.

4. Called Dell Support that week-end and sure enough after troubleshooting for quite some time they had me re-format hard drive to initial state. Guess what, webcam still doesn't work, still gives me error that no webcam connected. Dell support says they will send me a box so I can send laptop to their depot where they will replace the cover and screen assembly.

5. Box comes a couple of days later, follow instructions provided with box in regards to laptop and while I'm disabling password, it starts downloading updates; I hit power button and shut off computer. Ship laptop the next day.

6. Laptop comes back in a very, very short time. I turn on laptop and I get the screen that computer wasn't shut off properly; I'm thinking they've got to be kidding me, they never turned it on. Sure enough, the blue LED didn't light up and after boot up still no webcam detected. With the returned computer I also received a form letter stating "The system was diagnosed and extensively tested by certified technicians to ensure the problem you experienced was corrected." The form letter also has a Corrective Repair Action listing and guess what; nothing was checked and neither was a comment provided. I can only assume when they received the laptop at their depot, they put it in another box and sent it back; they may have replaced the cover and screen however there is no way for me to check that.

7. I call Dell XPS support and explain the situation. They remotely check the computer and determine that the webcam still doesn't work. They call the repair depot to see what was replaced, however, I was not informed how that discussion went. They inform me they will send out a technician with another webcam and a motherboard; this will definetely fix the laptop they claim since the webcam plugs into the motherboard.

 8. Two days later another technician shows up, first he replaces the webcam, no luck. Next he replaces the motherboard and voila the webcam still doesn't work. He calls Dell and gets put on hold just like the rest of us :) you gotta' love the system. Ok, so now I'm told they're bringing another webcam (this would be #5 for this computer) and a new cable that connects the webcam to the motherboard.

9. Bottom Line: I'm not upset, I'm amused. I'll provide an update after the next technician has been here.

I bet its the cable thats duff. It gets flexed every time you open and close the lid. I think thats whats wrong with mine!