how to tell if laptop screen is bad?

[lan101]

I am going to be picking up a Toshiba laptop from a customer of mine later today and they say the screen won't come on.

He also said it's not cracked or hasn't been dropped.

I've done a few screens so far on laptops, but they have been clearly cracked or broken, so it was obvious that the screen needed replaced.

On this one, how will I know that it's not the motherboard? Is there anything
I can do besides ordering a new screen and "hope" that that's the problem?

I plan on hooking up an external to see if video comes on that way, but still didn't know if there's a way to check board without a screen replacement in hand.


Thank you for reading,

Landon

 

[gazza]

If the laptop has no image at all it can be video card or LCD cable or the LCD panel. About the only non-invasive test you can try is to plug an external monitor into the laptop. This will determine if the problem is motherboard/graphics card or lcd cable/lcd screen. If you have an image on the external monitor then its likely to be lcd/cable/lcd screen.

Is the Displayed Image Faint?

A dim screen can be caused by three things;

1/ The LCD inverter which runs the LCD backlighting

2/ The CCFL backlighting fluro tube in the LCD panel

3/ The motherboard supplying signal & voltage to the inverter.

Most commonly (say 80% of the time) it's the inverter, 10% it's the ccfl tube in the LCD panel, and 10% it's the motherboard or the LCD cable from the motherboard to the LCD screen. Also remember that if it is a LED screen it will not have a inverter.

This is where having working spares comes in handy or might want to invest in a device such as the Laptop Screen Tester http://www.lcdparts.net/LST01.aspx

 

[Kitten Kong]

Hi Landon

You don't menton if this is a LED or a LCD screen.

First thing to check, is if it works on a external. If that fails, shine a torch onto the screen, as it may be the backlight / inverter. If you do see a faint image, then its time to take the bezel off, and see if the screen is led, or lcd. If its LCD then check / test the inverter. If its LED, then chances are its the backlight. Replacing the screen in this instance is the easiest method of repair imo.

If it does not work on a ext, and the torch shows no image, then your looking at either the cable harness, or mobo issue.

 

[Jobrien]

I keep several of my old CRACKED customer screens.. When a dead one comes in, I just quickly hook up the screen, if ti comes on Great, If not I'll try testing the other screen in a known good computer..

I can usually tell from the first test though.

 

[lan101]

Thank you guys for the replies!! I appreciate it.

As soon as I get it here shortly, I will give the model number and update if its dim or no display and if an external works.

Thank you,

Landon

 

[lan101]

Ok.

It is a Toshiba Satellite A665-S6070

http://us.toshiba.com/computers/laptops/satellite/A660/A665-S6070

According to Toshiba it's a 16.0 LED backlit display.

I hooked up an external monitor and the display comes on correctly.

I looked really close a couple times and the laptop screen is completely blank.

Thank you,

Landon

 

[RedFoxComp]

how to tell if laptop screen is bad?

It talks behind your back and borrows money with no intention of returning it.

(strange mood today)

 

[lan101]

HAHA I know a few people around here that borrow money with no intent on returning it.

I've looked up some screens for this model and some sites are bringing up 15.6 inch screens and others are bringing up 16 inch screens.

This web site here gives the exact "part number" that's on the bottom of the laptop.

http://www.sparepartswarehouse.com/...S6070,PSAW3U-04301C,Laptop,LCDs-Displays.aspx

According to that it is 16 in. I think I am just going to have to take it out and measure it for sure.

I didn't know if you guys have a better method to determine. I wish it was 15.6 because those are quite a bit cheaper.

Thanks again,

Landon

 

[Martyn]

HAHA I know a few people around here that borrow money with no intent on returning it.

I've looked up some screens for this model and some sites are bringing up 15.6 inch screens and others are bringing up 16 inch screens.

This web site here gives the exact "part number" that's on the bottom of the laptop.

http://www.sparepartswarehouse.com/...S6070,PSAW3U-04301C,Laptop,LCDs-Displays.aspx

According to that it is 16 in. I think I am just going to have to take it out and measure it for sure.

I didn't know if you guys have a better method to determine. I wish it was 15.6 because those are quite a bit cheaper.

Thanks again,

Landon

Get the number off the back of the screen

 

[dgiles79]

Get the number off the back of the screen

I would use the number off the screen too, it's the only way to guarantee compatibility. Sometimes the connector can be on different sides of the screen too.

 

[compnet]

About the only non-invasive test you can try is to plug an external monitor into the laptop. This will determine if the problem is motherboard/graphics card or lcd cable/lcd screen. If you have an image on the external monitor then its likely to be lcd/cable/lcd screen.

Just wanted to bold likely.. It is very possible for a bad mobo to give good external and nothing out to the laptop screen

If it does not work on a ext, and the torch shows no image, then your looking at either the cable harness, or mobo issue.

no external has what to do with the cable harness?? No external + no laptop image at all is mobo, ram, cpu, possible shorts/stuck in hibernation.


To the OP, if you want to fix screens, keep a cracked CCFL LCD and an LED powered LCD, from your other repairs that still work.. Most cracked screens still give picture and the CCFL/LED backlight will be intact. Pull apart the front bezel, plug in cracked screen, BAM you have your answer in 5 minutes flat.


Honestly the #1 issue with no image on the screen will be fixed by pulling the battery and holding the power button for 15-30 seconds. Last 3 laptops that would power on but nothing on the screen were fixed this way.

 

[Rosco]

Get the number off the back of the screen

^^^^^ this is the only way to be completely sure

 

[lan101]

***UPDATE***

I took a look at the screen and it's not the original screen.

The only number on there was J-4EBL538-J

It is a hannstar screen. I still don't know the true size by looking it up. The measurements however pretty well indicate a 16 inch screen I believe.

I can't find anything by searching this model number anywhere. If anyone has a source to try to find things like this, I would appreciate it.

Thanks,

Landon