laptop serious video problem

I have a Toshiba Satellite laptop M105-S3084 running Windows XP which today
started giving me scary video problems that I do not know how to figure out.

When I boot up the laptop, the screen shows the initial BIOS bootup screen
(with "click F2 to setup .... etc." at the bottom). This stays on for 1
second and the screen goes dark. The disc drive light goes on but nothing
appears on the screen. I have a BIOS password, so when I guess that request
has appeared and enter it and press enter and notice that the bootup into XP
continues (because the drive light goes back on) but this is done blindly
because nothing appears on the screen after the first second I mentioned.

I tried rebooting numerous times with the same result. Clicking on F2, F12,
F8 have no effect. Same behavior. Then suddenly it booted up normally with
everything visible on the screen. I assumed the laptop system was just
confused and now all is well. But when I rebooted it later, same problem
occurred. Again repeated attempts at rebooting all had the same result of
the BIOS screen appearing for 1 second followed by a blank screen. This
time I thought this was it and nothing would work. After about 30-40
attempts at rebooting suddenly it booted normally and this is when I am
writing this.

I have full backups at home but I am now on a trip writing from a hotel and
will not be home till after New Year. So data loss is not a problem but I
do not know what would be causing this weird video problem. Can you help?

After this successful bootup I ran the Toshiba "PC Diagnostic Tool" and
everything passed. I checked XP's Device Manager screen and there are no
yellow warnings anywhere. Don't know where else to look. The video is
integrated to the motherboard on this laptop. Could a failing cmos battery
do this?

Jeff