That's not it. Read more at http://www.google.com/search?hl=en&q=B154EW01+%2BVERSIONS&btnG=Google+Search
There is a possibility a combo of the Fn+Fkey is needed to enable the onboard display but I decline to research that.
The cracked LCD could create a short and burn out a component on the mainboard. The external VGA uses another signal path so while it's a good test of the system it says nothing about the LCD laptop components or hardware that drives the LCD.
And no, this will not be a software driver issue.
I have a Toshiba Satellite A105 - S4034 with a cracked screen. I've had it hooked up to a CRT monitor so I can still use it. I saved up some money to replace the cracked screen (model B154EW01 V.9) and ordered one from ScreenTek. They sent me a new one (B154EW01 V.1) that I've installed but can't get to work.
I unplugged the CRT before start-up. The LCD screen will light up but nothing's there. I've used the CRT to verify that the CPU is working properly, which it seems to be. I've checked the inverter and video connections, which seem to be ok. If I power up the laptop with the video cable unplugged, the screen is white. With the cable plugged in, it's still lit, but it's black.
Could the difference between V.9 and V.1 be to blame? Could the video cable connection be damaged. Am I missing a vital driver. Help me, Obi-Wan, you're my only hope.