Chosen Solution

Laptop is on but screen is black and caps lock led on.

Hi, Try the following procedure to get your laptop going.

  1. Remove the charger from the laptop.
  2. Remove the battery from the laptop.
  3. Press and hold the Power button on the laptop for 30 seconds to drain any residual power from the laptop.
  4. Connect the charger to the laptop, ensure that the power outlet is turned on and then turn on the laptop by pressing the Power button. (The battery should not be in at this stage)
  5. If the laptop turns on, allow it to boot all the way to the Windows desktop. Then shut it down in the normal manner.
  6. When the laptop has shutdown, switch off the wall outlet to the charger and remove the charger from the laptop.
  7. Reinsert the battery into the laptop.
  8. Reconnect the charger to the laptop and make sure that the wall outlet is switched on.
  9. Turn on the laptop and see if it starts.
  10. If the battery indicates that it is charging allow it to fully charge before disconnecting the charger.

My toshiba p845t had the same problem. No matter how I try, still no lock, and the bad thing is that CMOS button battery hid under inside, I open the bottom cover, but I don’t want to take the whole motherboard out, it’s too troublesome, so I cannot reset CMOS the button battery. I knew it’s the BIOS problem, after I drained out power, sometimes I can get the screen back, but after shut down or restart, it went back to blank screen. Here is what I do to fix mine by flashing BIOS:

  1. download the newest BIOS, make a bootable CD, surely if you get a chance to open Windows, you can run Windows version BIOS setup. Unfortunately, this toshiba BIOS driver won’t work with Windows 10.
  2. Hold ALT+F10 key before turn on power, hold them tightly, wait 1 or 2 or 3 miniutes, hold until computer reboot itself, and then you will got Toshiba screen, hit F2 key right away, get into BIOS setup, change boot from CD ROM first, save and reboot. Put in that bootable CD, and restart computer, if you get blank screen again, turn off power, and do alt+F10 key again.
  3. Computer will boot from CD ROM, and go to DOS mode, on the command prompt, just type Flash or something similar, which depends on the CD content you’ve downloaded. After BIOS flashing, it will restart itself. hit f2 key and go to BIOS setup again, change boot to Hard drive first. Save and reboot. My computer cannot find bootable device, so I went back to BIOS setup again, change hard drive settings, try 1 at once. I changed boot Mode, and everything runs great, even better than before.