Blank Screen toshiba equium m50-216 model sm57E

I'm having a weird issue with the laptop display... When the laptop starts.. from cold the toshiba logo flickers then the windows logo flickers then black... The screen however is still backlit... The laptop works perfectly apart from this. I can plug it into external monitors and it works fine but heres the weird thing..

I've plugged it into three different monitors it works in 2 (a packard bell ancient crt 4:3 and a dell lcd 4:3). It doesn't work in my wide screen acer... when it boots the toshiba logo comes up then the windows logo then just before you come to the windows welcome screen (that blue thing at the start) the monitor says no signal.

After awhile the display on the laptop will come on and be fine until I shut it down (generally... sometimes the screen does go blank and this is without touching it).

the blank display generally happens from when the laptop is booted after being off for awhile, say for example during the night... I simply closed the lid last night ie not shutting it down correctly then when I opened it this morning the screen worked perfect. there are no other display oddities... bad pixels, lines, annomylies of any other kind.

this problem has me baffled any help would be greatly appreciated
Cheers
Dave