Would be interested if anyone has experienced similar problem to this, I've only had the laptop six months, during which it's been back for repair three times.
First fault - froze during Windows 7 upgrade - repaired under warranty.
Second fault - battery wouldn't charge and faulty AC adaptor connection - again repaired under warranty.
Third fault - won't boot from battery most of the time - sent for warranty repair, returned today but still not resolved.
If I boot from battery only, it gets as far as the 'Toshiba' screen, then the laptop stops responding but the display gets gradually brighter and brighter with horizontal and vertical lines appearing until it resembles a sort of irregular tartan. I then have to remove the battery as none of the buttons will respond.
Plug in the AC adaptor , start up and it's fine.
Sometimes (with battery only) it fails to do anything at all, although I can hear the fan running. Occasionally it boots normally.
If I boot into windows using the AC power supply, then remove it once up and running, it works fine for maybe 30 to 60 minutes before freezing and the gradual reappearance of the tartan pattern.
Two weeks ago I called Toshiba Tech Support about this, they were unable to help and arranged for another repair. On return, the repair centre said No Hardware Defect Found, cooling systen cleaned and BIOS updated. This hasn't made any difference at all.
As long as I'm using the AC power supply, the laptop works absolutely fine.
I'm going to have to call Tech support again, but don't want to have to send it away for a fourth time in as many months
Is there an application which will test the battery for defects - is it delivering too much power to the system? I'd be interested if any one else has experienced similar problems.
If anyone is interested I have a series of photos in a .wmv file which I took of the screen behaviour . I invited RTS ( Toshibas Germany based repair centre) to look at this but I don't think they did.
I have read reports that batteries for laptops have been much more problematic than what is actually reported out in the wild (for example Windows 7 "incorrectly" stating how much power is left, when it actually was a battery problem.
I hate to say it but, I think you should contact them again and ask for a whole new replacement system. It sounds like the power coming from the battery may be faulty.
One more thing, do you have a spare battery to try out? Or someone with the same laptop and ask them to borrow the battery?