We are using VMWare and creating VM guests where we execute QTP v11 tests. Our QTP tests are stored in ALM v11, and we kick them off using Microsoft Task Scheduler to start a program that uses the TSScheduler object of the ALM OTA API.
Our VM guests are set up to never sleep, never lock, never go into hibernation or power saving mode, and never start the screen saver. And yet, after a period of inactivity the screens go black.
When that happens the scheduled task still initiates the QTP tests which do successfully begin to execute, but all they see is a black screen.
We have tried adding to the initial script to do a series of mouse clicks to wake up the screen. That doesn't work.
If the tests are in the process of running, but failing because the screen is black, if we connect via Remote Desktop or open the console using vSphere, then the screen wakes up and the tests can "see" again.
We've talked to our local VM experts who can't come up with any reason why the screen on the VM would go dark due to inactivity, when all the power saving options for the guest are turned off.
Are the VMs set up as a particular brand of machine? I 'm not sure if VMs work that way. But perhaps ask the vendor that uses that flavor of O/S what could be making the screens go black.
Try running something like Caffeine on the VM, you might be able to schedule it to kick in 5 minutes before the test is due to start. I have seen a similar issue with black screens when trying to take screens shots during tests.