I've had 3 notebooks in shop recently that had no display --> not even a faint one. Additionally, there was no display on an external monitor for 2 of them. All powered on and went through at least some POST sequence (removed memory and they beeped). Two Compaqs and a Toshiba.
My experience with notebooks is somewhat limited but assume that inverter and/or backlight failure is not the cause. Those with no external display would appear to be motherboard or graphics adapter related (integrated graphics).
Looking for assistance from notebook experts in determining root cause. Thanks in adavance.