Screen is Black even when the machine is on

The Toshiba A105 notebook computer is made for mobile computer users who need optimal processing power. The LCD screen is a 15.4 diagonal widescreen with TruBright technology. The laptop has a fast hard drive access rate that is in the 3ms range for the paging and access of data. There are problems that can occur with the Satellite A105 that can be solved by knowing what to look for when troubleshooting the system.

Black Screen Problem Black screen problems can occur when the Satellite A105 backlight is burned out or the inverter is not working correctly. The backlight can be replaced with a new LCD bulb manufactured for LCD screens. The inverter is a housing unit that controls the voltage to the LCD screen. The inverter must be replaced by a compatible A105 Satellite inverter unit. Power Problems b> During the power-up phase of the laptop, the Satellite A105 will quickly turn off without signing into the Windows Operating Screen. The problem can be due to a faulty power adapter that is not supplying the right amount of voltage to the system board. You can also check to see if the unit that houses the power plug is loose, which also indicates lack of voltage or electricity going to the board for power up operations. Hardware Conflict Problems b> Hardware conflicts can cause system errors or "freezes" by loading a new hardware component into the same hardware I/O address. The Satellite A105 has designated input/output addresses for peripheral devices, such as hard drives, video drivers and other hardware functions. To solve hardware conflicts, use the Control Panel "Hardware" device function to see which hardware I/O addresses is not being used. b> Audio Not Working Correctly b> Loading a new audio program can cause the audio codec for the Satellite A105 not to produce sound. The audio codec can be restored by loading the "restore system disk" for the A105 laptop. The restore menu provides options on certain components that you want to restore. If you pick the option for audio, the program will restore the audio to its factory settings. b> On-board LAN Switch Not Working b> The Satellite A105 is automatically configured to detect T Base 10/100 Ethernet networks. If the laptop does not recognize the on-board LAN switch, check the system setup to examine if the LAN switch is on. If so, a firmware update may be needed to upgrade the BIOS.

LCD screen cracked, and Three even strips going across? Doubtful. Haven't seen it but I always have my mind open.

Three strips that are irregularly shaped? Look like glass that has cracked?
'Jagged edges'?

LCD screen is broken.

Three even strips indicates to me, that there may be a problem with the Video Cable. Then the screen Inverter is next in the diagnoses.
My money is on the Video Cable.

ALL power removed, Anti-Static Precautions FOLLOWED, I would check out the graphics chipset first.

1) Laptop OFF, monitor OFF, connect a VGA monitor to the VGA port on the laptop.
Left rear side. This is an example of a VGA Cable, and VGA connector. (VGA port on a laptop ),

http://en.wikipedia.org/wiki/VGA_connector

(Color of connector does Not matter. It is generally Blue, though)

You can use a CRT type of monitor, (Looks like a small TV), or a flat LCD screen monitor if it has a VGA cable.

2) Turn the monitor on. If a CRT type allow it to warm up.
Turn the laptop on.

There are at least 3 display options available;
1) Laptop internal monitor ONLY
2) Laptop internal monitor AND external VGA monitor
3) External VGA monitor ONLY

Press, and hold down on the Fn key, and at the same time tap once on the F5 key. (The F5 key is the Display Toggle-Over key)

No display on external VGA monitor?
Hold the Fn key down again, and tap once more on the F5 key.

Is the display on the external VGA monitor, the same as the internal monitor of the laptop?

Problem is the graphics chipset.

Display is fine on the external VGA monitor?
Problem is the Video Cable, screen Inverter, or LCD screen.

Video Cable:

A) http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/big/Toshiba-Satellite-A105-14.jpg

Switch Cover removed, Keyboard removed. Shows you where the Video Cable plugs into the motherboard.

B) http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/big/Toshiba-Satellite-A105-21.jpg

Palm Rest Cover you can see the white rectangular connector, for the motherboard side of the Video Cable, at the top left.
It's above the black cable, and near the screw hole.

The Video Cable leads from the motherboard, up through the left Hinge, and into the Display Assembly.
From there it connects to the screen Inverter, and back of the LCD screen.

http://www.ebay.com/itm/Toshiba-Satellite-A105-6017B0050801-LCD-Video-Cable-Genuine-OEM-Laptop-TESTED-/290754851160?forcev4exp=true&forceRpt=true

In the photo, (You can hover your mouse cursor on it to enlarge), the right side connector plugs into the back of the LCD screen.

The black connector to the far left connects to the motherboard.
The small white connector at the top with the Red, Green, Black, etc wires, connects to the screen Inverter.

(The small Black cable, that comes out from the black motherboard connector, is a Ground wire )

Due to the close proximity of the Video Cable to the left Hinge, it can be pulled on from just normal opening, and closing of the laptop over time.

This means the Video Cable connection on the motherboard side could be loose, or the LCD screen side, or both.

The diagnoses is to PHYSICALLY check BOTH connections. A loose connection at the motherboard, or at the back of the LCD screen could be so small in distance, that you will not see it with the human eye.

Could also result in damage to the Video Cable.
View the Video Cable with the Switch Cover removed, and see if there are any obvious signs of damage to the sheath of the cable.

If there is there could be damage to the tiny wires inside the Video Cable. (Stretched/Broken)

Use a multimeter set to OHMs, to check all wires inside the Video Cable for continuity, or have a 'Mom and Pop' computer store check it for a few bucks, or replace the Video Cable.

Video cable connections are tight? Video cable continuity check checks out OK?
Screen Inverter.

The test for a screen Inverter is to use a sensitive multimeter.
Read fairly expensive.

http://www.fonerbooks.com/test.htm

Not having access to a sensitive multimeter that you can use, means just replacing the screen Inverter. Seems like 'part changing', and it is, but you have to work with what you've got.

http://www.sparepartswarehouse.com/Toshiba,Satellite,A105,Laptop,Inverters.aspx

Find THE model number for your laptop, and the correct screen Inverter. A screen Inverter, and an LCD screen are a MATCHED unit.

Screen Inverter is checked out to be OK, or replaced, and symptoms are still the same, the problem is the LCD screen.

Remember, the first part of the diagnoses was to see if the divided parts were EVEN going across, or jagged and irregularly shaped.

Jagged in shape, and not even strips going across, means cracks in the LCD screen.
Replace.

http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/remove-replace-LCD-screen-1.htm

[ Main article for A and B links above;

http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/remove-motherboard-1.htm ]

For additional questions please post in a Comment

Regards,
joecoolvette

Use the VGA port to connect an external monitor, this will get you up and running temporarily until you can fix the screen, it sounds like you have a faulty inverter.

Here, I found this:
Toshiba Satellite A105. How to remove and replace laptop FL inverter and LCD screen.

http://www.irisvista.com/tech/laptops/Toshiba-Satellite-A105/remove-replace-LCD-screen-1.htm

If you've replaced the LCD Panel already, then chances are good, the failing part may be the FLR inverter. It's a thin little chip about 3 or 4 inches in length that bridges the connection between the LCD and the motherboard. It's location varies from computer to computer though, so you may have to check with manufacturer documentation. They're not too terribly expensive to replace though, much cheaper than the LCD panel, anyways.

If you pull off the top part where the speakers are above the key board your monitor might be unplugged. i had the same problem with one

Hi, ok friend must identify 2 things, the first thing is if the screen in black appears since it power on the equipment and changes are not obvious at the back of this one, of being like that this means that it can have faults to level of the card of video or of the LCD, now well, if it looks for a light source and at the back of the LCD to show the dark screens, it indicates that the FL Inverter this one damaged and must replace.

You need a new lcd, The connectors are bad...

Hi, This is definitely a loose connection problem.
Does the screen go completely black or just a part ?
If its just a part, LCD is defective. You may have to change the whole LCD screen. You can get one for ~180$ from ebay
If the whole is turning off, I guess the power cable might be little loose.
You can open the LCD panel and check if you know what you are doing.
Else take it to a normal technician and ask him to open the LCD panel and see it.
:)

the inverter maybe going bad. go to ebay get a cheap toshiba satellite a105 lcd inverter.bam the problem fix oh you would need a screw drivercause this is a diy project no need tosend it out link me if anything [email protected]