Toshiba Satellite Blank Screen

So I've looked around many places and have tried many things.
My Toshiba satellite m105-s3041 has what seems like a frequent problem in Toshibas where the screen just turns black in the middle of doing things. I know it is not the backlight, because I can increase and decrease the brightness using the fn f6/f7 keys. Also, if I shut it, it will hibernate as it is supposed to, and the screen starts working again when it starts to hibernate (you can see the windows message that it is preparing to hibernate). So thankfully I don't lose any data when this happens.
I have replaced the LCD inverter with a new one, and I thought that did the trick, but apparently not. Today it happened again. I tried a different trick to see if that would help. I plugged in a monitor to my laptop. I did fn f5 until something happened. It worked only when set to CRT/LCD at the same time. Not when reset to LCD. It also did not work when set just to CRT.

This only occurs when the computer is not plugged in and is running on battery (although plugging it back in doesn't fix the problem without hibernating it first). I have tried 2 different batteries, and that didn't change anything (except with the smaller battery, it was less likely to happen because there is less battery life).

My next step should be replacing the ribbon, even though I don't think that's the problem now since it won't go to an external monitor when the screen turns blank.

 

This sounds like a power issue not an LCD issue to me.
You could try disabling all power saver options, Toshiba Power Saver etc. Disabling Hibernation and CPU gating and running your notebook from the default windows power management when on battery.

Have you checked the Toshiba site for the latest drivers (not bios)?

 

User told me that it sounded like the computer was starting but nothing appeared on screen. I get the laptop home and….it boots up fine, I can see the screen.

I take it apart to check connections. ribbon to back of monitor is tight, ribbon to motherboard is tight. Put it back together. I walk it around a bit and jostle it to recreate ‘light travel’. I put it down, pick it up, repeat.

Start it back up, no monitor, but there is a back light. Take it apart, connections solid. When I do unplug/plug the cable from the motherboard the monitor does flicker back on.

I just plugged in an external monitor and that comes up fine. I hit fn-f5 and that cycles through the monitors and the laptop screen does come on. I unplugged the external, shut down the notebook and came back 5 minutes later and it turns on fine even without the external monitor.

Thoughts?