I've got an HP DV7-7012 running Win7 Pro (64 bit) with hardware and BIOS known to be good (dual-boot proves it), but a weird problem occurred when I did a driver update.
The issue is an interaction between Intel's HD 4000 driver and Nvidia's GEforce 650M. If the Intel display adaptor is enabled the internal LCD and external screens become black as soon as the windows login screen appears (or, actually, doesn't appear). The boot sequence is displayed fine, but of course that uses the default non-PnP VGA driver.
When the screens are black, PnP is detecting a new monitor when it's plugged in (window's "bing-bong" sound occurs), but nothing is displayed (the monitor LED may be on, but all the pixels are turned solidly off). Unfortunately, once the screens have gone black, even a reboot won't make them come back (i.e., the BIOS screens are also black). I have to physically remove all power for a few seconds to reset whatever bit is stuck the wrong way.
Tried a variety of driver versions (both for the Intel gfx and the Nvidia), uninstalled/reinstalled/rebooted several times, did a Windows boot repair cycle and a couple of system-checkpoint restores. No luck. The only way I can use my machine now is to disable the Intel graphics chip, which effectively disables the Nvidia as well...that gets me back to the "safe VGA" dumb graphics mode. That means no mulitple displays (normally, I use three).
Possible theories, given all the testing I've done:
- Intel chip has some configuration data stored somewhere that puts it into no-display mode. Is there some utility or regedit hack that could test / correct this?
- Intel driver is not properly connecting to the monitors' drivers--something is missing or corrupted. Ditto with the utility/regedit question.
- Intel driver is not properly connecting to the Nvidia drivers, hence it has "no input". Ditto again.
- Intel driver is fine, Nvidia driver is messed, hence no output delivered and Intel chip is properly rendering a whole lot of nothing. Again with the ditto
- I'm stupid and I've missed something obvious. The remedy here is your responses!
Going crazy with the prospect of having to reinstall windows just to make the graphics adaptor work.
Help?!?!?!