I turn on laptop and only a white screen is

A white screen usually indicates a problem with the video harness connecting the motherboard to the LCD screen, or it can be a problem with the LCD screen being defective itself. You could try to reseat the video harness and see if that helps, as sometimes the connection has just become loose.

If the video works fine (whether in the BIOS/ Safe Mode) on the external monitor then I would not see the video card as being faulty. As you said the graphics seemed "weird" however on the monitor, then try reinstalling the drivers and see if that helps with that issue. If you cannot access the BIOS on your laptop, then it seems likely that either your video harness is faulty (you said the connection was not loose), or the LCD itself is defective. LCDs are expensive to replace, so I'd suggest ruling out other possibilities first.