Reposting in Video Forum, accidentally had in General Hardware at first:
I just installed Windows 7 Pro and all drivers on an E6420. After updating to BIOS version A16, NO video image appears on the laptop screen prior to Windows loading. On either cold or warm boot, neither the Dell logo, the BIOS version, the progress bar, nor the F2 or F12 prompts are seen. I can get into the BIOS if I'm lucky enough to be pressing the F2 key at the right time, but none of the BIOS information appears on the laptop screen, either. I know this because when I connect an external monitor to the external VGA connector on the side of the laptop (not using a dock), I see the Dell logo, F12 prompt, etc, on the external monitor for about 1.5 seconds and I can press F2. I can also see all the BIOS setup information on the external monitor. If I disconnect the external monitor while in the BIOS, the image does not then display on the laptop screen, it remains blank. I've found no current posts on this problem. If anyone has an idea how to get the video to work, I'd appreciate any and all help. Re-installing the video driver is not likely to help, as the video driver works in the OS, after the POST process.
Also, is it normal for the POST screen to display for such a short time? The BIOS Fastboot setting for POST Behavior is set to thorough, but the display time for the Dell logo, F12 prompt, etc, is still very short. Thanks in advance. -J
A co-worker suggested I try using the FN-F8 key combination to see if that would help. Here are the results:
As long as the external monitor is connected prior to turning on the power, the image displays there automatically.
I booted it up with the external monitor connected, saw the POST on the external monitor only, pressed F2, went into BIOS setup on the external monitor, then pressed Fn-F8, and the image switched to the onboard laptop screen.
So I powered down, disconnected the external monitor, powered on, pressed Fn-F8, and it did not cause the POST image to appear on the laptop screen.
Then I powered down/up with the external monitor disconnected, pressed F2 a bunch of times right after turning on power and, of course, no image displayed on the laptop screen, but I know it was in BIOS setup, because Windows did not load. Then I connected the external monitor and pressed Fn-F8 and the BIOS setup displayed on the monitor, so it didn’t matter whether the monitor was connected prior to turning on the power. I pressed Fn-F8 one more time and BIOS setup displayed on the laptop.
Still not resolved, but at least I now know that the laptop will display video onboard prior to the OS loading, nothing wrong with the screen itself. I really think this is a problem within the new A16 BIOS, but I need someone else to test on another E6420. Thanks,