My portege M400 wont start up. The led light is blinking orange in a steady even pattern. I have tried removing the battery but that doesnt change anything. The screen is blank, and the fan is loud.

SOURCE: toshiba M400 tablet wont start

I think it might be the systemboard here.. but I strongly don't advise taking it apart yourself unless you know how because it can be tricky and you must be grounded

SOURCE: toshiba M400 tablet wont start

I've had this problem intermittently on my Toshiba M400, and it recently became bad enough that it was failing to start on most attempts, and crashing soon afterwards if I moved it. Prodding the heatsink to change its position may have helped, but this could have been due to chance. It also had a habit of resetting itself when leaning on the left side of the keyboard when typing, but not when using an external keyboard. It's always had occasional crashes under high CPU load, causing the machine to freeze and the fan to go up to maximum. BIOS updates improved this initially, but in recent months it got worse again, especially when using Virtual PC unless hardware virtualisation was disabled.

I've just stripped down the laptop using the guide suggested by thiscomputer at http://www.irisvista.com/tech/laptops/Toshiba-Portege-M400/take-apart-tablet-pc-1.htm (good find!). Many parts are more fragile than in a desktop PC, but otherwise if you're used to taking stuff apart it shouldn't be that big a deal. You'll need a normal and small crosshead screwdriver (jeweller's screwdriver set works fine) and space to lay out the screws in a pattern so you remember where they go - consider making notes.

I fixed two things that could have been a problem: Firstly, a fair amount of dust was blown away with a hairdryer and vacuumed from the heatsink. Secondly, the pink thermal grease that couples the CPU to the copper heat pipe appeared to have all squeezed off the CPU die and had accumulated around the sides, possibly due to the small freedom of movement in the heatsink being repeatedly shaken. The grease was still soft so could be scooped back onto the die with a flat-bladed screwdriver. I also bent the legs of the Y-shaped CPU-to-heatsink retaining clip so that there was a greater downward force on the CPU. I figured this would improve thermal contact, especially if the clip had naturally bent and come loose over time. Removing the CPU itself didn't show any damage, but might have improved the electrical contact when reinserted. Be careful when screwing the Y-shaped retainer back in - because of the springy nature of the legs, if the screwdriver slips the screw will fly across the room and you'll have to hunt for it :-) The other thing to note when reassembling is that the wi-fi on-off switch engages with the lug on the motherboard, if this is wrong you won't be able to move the switch and the actual state will be the opposite of the switch position.

Finally, after I reassembled it still refused to start. I noticed the DVD drive wasn't properly flush with the case, and on removing the DVD drive it started. Close inspection of the drive and laptop connectors revealed a small metal tab had come loose, and the laptop continued to work with this tab removed and the drive reinserted properly. I removed and swapped some memory modules while experimenting with the DVD drive which also had some effect - it's possible that an ill-fitting DVD drive bends the memory above it and affects the contact. It's entirely possible that this was the only problem to begin with, and that playing with the CPU made no difference, so maybe check this first! But whatever it was, happily my m400 seems to be operational again.