After encrypting laptops, a few laptops have been shutting down when trying to login to the pre-boot login. Some machines seem to be experiencing overheating issues, but doesn't always seem to be the case. We can take the hard drives out and install them in other chassis and they work fine. Is there anything that could possibly affecting the BIOS?
Yes, we are checking for bad sectors. Like I said we can take hard drives and install in different chassis and they work fine. Many different models, but MFG is HP. We have been replacing MB and heat sinks.
what makes you think it's a thermal issue? have you been getting SMART errors?
the pre-boot code does not do any power management, we kind of expected the machine to be powered on, logged in and then Windows would take that over. I have experienced situations though personally when my laptop has been bumped in my bag and turned itself on, then sat at the pre-boot screen for an hour with the CPU on max and got insanely hot.
The problem is the machine powers off while sitting at the login prompt. The software has no power management built in, so that infers that the hardware is involved (the bios is unloaded when the pre-boot is running) .
The most obvious cause would be that the machine ran out of power, or as you say, the cpu detected a thermal overload condition. I doubt the drive is bad - nothing indicates corruption at all. I don't see any link between bad drives and powering off. if the drive was bad you'd get error messages on the screen.
So the questions I guess to ask would be a) did the battery die? b) was the machine really hot when it turned itself off?
The machines are docked and plugged into wall or undocked plugged into wall. So, power doesn't seem to be an issue. We shut down one laptop for a day and allowed it to cool if that is what it needed and it ended up doing the same thing again. (shutting down at pre-boot screen). I mean 50 or a 100 hundred out of 18,000 doesn't really seem like bad odds, but it makes you wonder why and what.