I'm at my wits end here. A customer brought me a Lenovo T400 thinkpad running Windows Vista Business 32 bit. The backlight on the display was out. He had been using the laptop connected to an external display for awhile now. Since I wasn't sure if it was the light itself or the power inverter, I ordered a complete replacement display. I verified it is the correct display and replaced it. It booted up without issue until Windows fully loaded. Once Windows fully loads in normal mode, the display goes completely dark (no power to the display at all). If I connect an external display, I can check settings and such. If I boot into safe mode, no external monitor is needed. The LCD display works fine and I can check whatever I need to check.
So, the new display works in safe mode but not normal mode.
This leads me to a driver issue. When I uninstall the display driver and reboot, it will boot into normal mode and automatically reinstall the driver. Then, of course, it tells me to reboot. When it reboots, the display goes off again just as Windows is fully loaded in normal mode, just before you would see the Welcome screen..
BIOS display settings are set to Internal display/ThinkPad LCD.
FN-F7 once, twice. or thrice does nothing. The display still never powers on.
When connected to the external monitor, I right click on the desktop and select Graphics Options. This brings up Intel graphics software, which only shows the externally connected monitor. It doesn't show the display so I can't change any settings for the LCD display.
Here's the really strange part that has thrown me for a loop. The power settings are set so that pressing the power button puts the laptop to sleep. With no external monitor connected, if I boot it into Normal mode, the display is dark. After windows is fully loaded (by listening to those infernal windows load sounds), I can press the power button and put it to sleep. I wait a couple of seconds and press the power button again to wake it up. The display works fine from then until it is rebooted again.
So, basically, this laptop will boot normally, but the display won't work unless you put the laptop to sleep and wake it up again. Then, the display will work perfectly.....................until Windows is rebooted again.
Thanks in advance for the Frustrated Possum.
I'm certain this is a driver conflict issue with the display driver, I'm just unsure how to diagnose which driver is the culprit