Toshiba satellite L355D-S7901: no display

[shashgo]

Windows Vista. 3GB Ram. The laptop starts up, but I dont know if it boots up or no, cause there is no video output on the laptop LCD.  I hooked it up to an external monitor and pressed the fn+f5 repeatedly to switch monitors. But I dont get any output on the external screen either.  What are the different things I need to check to see what the problem is with the video output

[patio]

Try a bootable CD and see if you get anything onscreen or not...
This will determine if it's the OS...or possibly the vid chip.

[shashgo]

But if Im not even seeing a toshiba splash screen or anything then I shouldnt be able to see anything else even if I put in a bootable CD right? 

If the problem is with the display system, then whats steps would I go through to see whether the problem is with the video chip, or the inverter, or the lcd ?

Ill try your bootable cd method in any case.

[truenorth]

What exactly does the laptop screen display? I mean is it as if the laptop were off or do you get a black screen that never changes. Does the computer appear to be otherwise functioning such as you can hear fans/lights are on such as "above the "numlock key or the light that indicates powered ( presuming adapter is plugged in) as well as the one beside it that indicates the computer has been turned on. If you just turn it on and wait do you ever hear any sounds indicating the computer is booting? Have you tried to enter "safe mode"? Did this just occur all of a sudden or was there something abnormal that preceded it?truenorth

[shashgo]

Laptop screen is just black.  It doesnt show any signs of coming on, you know like when the screen starts out black and then shows a little flicker like the backlight is coming on or something but yet nothing displays. 

The fan turns on, I can hear the hard drive start, the lights on the front edge of the laptop that show power and the hard drive light up and stay on.  I cant enter safe mode cause the screen shows nothing.  I hooked up the laptop to an external monitor and tried the fn keys to get the external display but ..nothing.  How would I know if the lcd is bad, or the inverter is bad, or the video chip is bad?  Maybe the video chip maybe loose or something so when I open the laptop how would i know where to look?  Also could it be the inverter or the lcd that is not plugged in properly, or could it be a bad cable

[patio]

Did you try a bootable CD yet as suggested ? ?

[shashgo]

Patio,
Yes, I did try the bootable CD, still nothing.  But why would the bootable CD give anything on the screen if I got nothing otherwise?

[patio]

Because it eliminates the Operating System as the culprit as it operates outside of that...
If that produced no results it's certainly the onboard vid chip...
Replacing/fixing it may be more than the laptop is worth so you will have to make that determination yourself.

[shashgo]

patio , i guess that is true, but is it possible that maybe the cables going to the video display are bad or that the inverter is bad or something?  And is there any way to find out that stuff or do I just need to open up the laptop and check?  And also is it possible that the video board could have gotten loose, if  the video board clips onto the motherboard

[patio]

It could be any or all of the above you mentioned...
I'd look up a dis-assembly manual for reference 1st before you dig into it.
To check the inverter some people shine a flashlight on the screen after letting it boot up fully...

[truenorth]

On this one "To check the inverter some people shine a flashlight on the screen after letting it boot up fully..." doing so in a darked room will help the observation. But i personally doubt that one as an external monitor should not be affected by that fault. As patio states i lean to a video card issue (but could be loose too) =. Banged or dropped this laptop coincident to this occurrence?truenorth

[L. Hernandez]

It could be any or all of the above you mentioned...
I'd look up a dis-assembly manual for reference 1st before you dig into it.
To check the inverter some people shine a flashlight on the screen after letting it boot up fully...

Yes you have to do that for sure. I really love to work with qualified people.

[L. Hernandez]

It could be any or all of the above you mentioned...
I'd look up a dis-assembly manual for reference 1st before you dig into it.
To check the inverter some people shine a flashlight on the screen after letting it boot up fully...

Actually i want to know if the manual is 100% accurate also.

[camerongray]

Since it doesn't even reach the POST screen (Toshiba logo) the problem is no the OS.

Trying a flashlight would certainly help to tell if it's the backlight.  I would also try unplugging the internal screen (If you are confident enough) then trying the external, that will eliminate the need to try switching outputs as the laptop will default to the external screen if it cannot find an internal screen.  If it still doesn't display on an external monitor then chances are the problem lies somewhere other then the screen (The L300 *will* display on an external with no internal connected, I've done this before)

[patio]

He hasn't been back since February...