The last post in this discussion is almost 3 years ago. My Venue 8 Pro is still working, mainly using it to listen to audio streams because radio reception is so bad in my basement. With the surge in video conferencing, I was curious if it could support Zoom et al. Guess what? No camera. Meanwhile, my older iPad 2 does.
The Device Manager does not have Cameras at the top level but does have one under Imaging devices. It is currently named "Intel(R) AVStream Camera" dated 2015-07-04 (wasn't that a holiday?) after Update Driver went off in search on the Internet. Previously, it was "Intel (R) Imaging Signal Processor 2400". Under "System Devices" are "Camera Sensor MT9M114" and "Camera Sensor OV5693", both of which have reportedly "The best drivers for your device are already installed" and date from 2013.
Dell Update says "The system is up-to-date" and was last updated at the end of 2018. I don't remember if the camera was working then.
Eureka? Camera is working again - front and rear. Don't quite know why. I went through the process of deleting the Camera under Imaging Devices and installing the Z3000 Series drivers. On the second reboot after installing the drivers, I got the message that it would have to restart again after installing the Intel Imaging Signal Processor 2400 driver. That came as a surprise because no such driver is found in the Z3000 series drivers. That driver was there and "working properly" when I started this exercise today but I neglected to record its date and version. The driver that now seems to be working is dated 2013-11-28 version 603.9600.1948.31252.
On the Microsoft Update Catalog is a (later?) driver for the 2400 with date 2015-11-24 and version 20.10568.5749.852. I don't know if the date and version number are those of the driver or of the CAB file but I think I should leave well enough alone. Maybe that was the Windows Update that made a mess of the camera.