After replacing the broken LCD screen and connecting it to the system according to the manual, there is nothing shown on it. The computer works fine when it is connected to another computer. Any clue as to where I should look for? Possible causes? Loose connection? Short circuit? Others? Thanks

Backlighting is accomplished by a series of LED's.

Light Emitting Diodes

As such no screen Inverter is used. This we can count out, then.

Display shows good on external monitor. Means graphics chipset is good.This we can count out, then.

All that leaves is Video Cable.

Provided of course, that it is not a defective LCD screen, or the wrong one was sent.

Video Cable connections are not tight at motherboard, and/or back of LCD screen.
Visual inspection alone, will NOT do.
Physically trying to plug in tighter, is required.

Connections proved to be tight, then the Video Cable needs to be removed, and a continuity test performed on it.

A multimeter is set to OHM's (1K), and every wire in the Video Cable is checked for continuity.

This test sends electricity through the wire, and if electricity flows through the wire, then the wire is deemed Good.

If electricity does NOT flow through that individual wire, then the wire is deemed broken.

An assistant is also used, to gently wiggle the cable.
If an intermittent reading is shown on the multimeter, then the wire is broken.

Replace Video Cable.

Suggest remove Video Cable, and take to the nearest computer repair shop; and have the resident tech check it.

If they do not know how, get out of there! You are talking to a parts changer, and not a technician.

OR,
Replace the Video Cable,

http://www.ebay.com/itm/Toshiba-Satellite-C855-C855D-LCD-Video-Cable-6017B0361601-/360625329703?pt=LH_DefaultDomain_0&hash=item53f6f1d627

Example. Not advertising for seller nor website.

For additional questions please post in a Comment.
Regards,
joecoolvette

First :
Try connect your laptop to other monitor ( crt or lcd ) if it looks normal on the monitor, it means your LCD laptop is broken.


Somestime often open-closed this LCD Laptop, may broken your Flexy data kabel of your LCD laptop.

Anyway Thx

Strange could be video card issue or broken screen. try connecting it to TV or another monitor see if the picture is clear than video card is fine and display is damaged

-check the cables on the monitor and disconnect and reconnect it
-if issue still persist you can check the cable of the monitor for broken pins (vga cable the one with blue connector)
-if there are broken pins then the cable could be the problem
-if not you can try to connect the monitor to another computer or connect the computer to another monitor
-if you connect another monitor to the computer and it works fine then the first monitor you have is broken
-but if you connected the monitor to another computer and it works then it could be the video card of the computer.

Hi,
First, Please confirm that if LCD is blank then can you see the images in view finder ? If not then the CCD IMAGER is faulty and if LCD is blank and you can see the image in view finder then then a Flexible board which connect the LCD with the main unit is broken, Please replace these parts according to the symptom. Moreover, for your ease pics are shown below of both parts with part number.

First pic is for CCD IMAGER
second pic is for flexible board.
Thanks

Hi,
It would physically be in the LCD screen of your computer. If the monitor is working fine therefore there is nothing wrong with the video processing output or the drivers in the operating system. It would be in internal crack on the LCD or a loose connection with the LCD screen and the motherboard.
Its best to have your laptop checked by a service technician and dont just disassemble it by yourself to prevent accidents. Worst case is that the LCD needs to be replaced if really found cracked/defective.
Hope this helps.

Sounds like your "Backlight" is not powering off.
Are you sure it is an exact replacement?
Check ALL your connections again, perhaps ya have a bad one...?
Have you got the latest drivers?

Well you either have one of 3 things wrong with the computer:

1. the video connector on the logic board is broken or not making a full connection
2. the video cable from the logic board to the LCD panel is damaged.
3. the LCD panel is dead

if evrything ok in your fone except the screen(LCD). the problem is your LCD maybe its just a lose contact or or the LCd is broken maybe it can help to you ^_^