Since late last year, I’ve been upgrading our desktops and laptops at work from Windows 7 to Windows 10. For each machine, our process has consisted of doing the free upgrade to Windows 10, then doing a clean install. For the most part, the transition has gone smoothly, but I recently ran into a problem with an upgraded HP ProBook 6460b and accompanying HP docking station (VB041UT#ABA). Both pieces of hardware were purchased in 2011, so we’re not talking about brand new equipment here, but the computer does what we need it do.
The problem
With Windows 7 installed, the problem laptop output video through the DVI and VGA ports. After I installed Windows 10, however, if a VGA monitor was connected, it would display only at the laptop’s native resolution of 1366×768, and the external monitor connected via DVI would fail to find a signal.
If no VGA monitor was connected, the DVI monitor would display the HP logo on the boot screen and the Windows logo as Windows began loading, but then the screen would go black. The power button on the monitor would remain lit up like it was getting a signal until I opened the lid on the laptop; at that point, the monitor would lose its connection and display the “check cables” message, and the only way to get it to display anything again was to close the laptop’s lid and reboot.
Troubleshooting
We previously upgraded another 6460b with the same model docking station to Windows 10 without running into any issues, so I had no reason to believe the laptop model in question was incompatible. I tried swapping cables, monitors, and even the docking station itself with another identical docking station that I knew worked with a laptop upgraded to Windows 10. I compared the laptop’s display settings, power settings, and graphics driver version with the working laptop, and everything was in sync.
After checking the obvious things, I began my online search, and finally ran across a forum thread in which someone mentioned having to update BIOS on a Dell laptop to correct a similar problem. It seemed like a long shot, but I restarted the problem laptop and a working machine, pressed Esc on boot and then F1, and checked the BIOS versions on each computer. Sure enough, the laptop that output video correctly boasted BIOS version F.60, while the problem laptop reported version F.42.
I downloaded the latest BIOS from HP (version F.61) and let the flashing process run over a weekend. Once the BIOS was updated, I docked the laptop, and video was output to the DVI and VGA monitors, both of which displayed at the correct resolutions.
Troubleshooting, part 2
All appeared to be right with the world until I rebooted the laptop, at which point the computer forgot what resolution it should be using on the external VGA monitor, and reverted to the laptop’s native resolution. I opened Device Manager, expanded the Monitors grouping, and uinstalled the Generic P&P Monitor listed there, then rebooted, and the VGA monitor was detected correctly once more.
Following another reboot, however, the VGA monitor once again reverted to the laptop’s native resolution, and after that point, uninstalling the generic plug-and-play monitor from Device Manager had no effect on the setup’s performance.
After fighting the issue for a while longer, I finally opened the Intel Graphics and Media Control Panel, went to the Display section, and added a custom resolution (1280×1024) and refresh rate (60Hz) appropriate for the monitor connected to the VGA port, and rebooted again. After that, I went into Windows display settings and clicked through to the advanced display settings, and I was able to select my newly-added custom resolution for the VGA monitor.
Summary
The DVI output problem was resolved by updating the laptop’s BIOS. The BIOS update initially appeared to have fixed the VGA resolution issue, too, but I ultimately had to define a custom resolution in the graphics control panel to get away from the laptop’s native resolution being displayed on that second external monitor.
Although the laptop detects when something is plugged into the VGA port on the docking station, it appears to be failing to detect exactly what that something is, reporting only that a generic plug-and-play monitor is connected. I can’t explain why it worked immediately after the BIOS update without a custom resolution defined unless there is some sort of intermittent hardware problem, but the user has reported no display issues since I added the custom resolution and swapped the laptop into place.