laptop no display on screen

[Srijib]

I am able to hear the welcome sound of Windows but no display at all. the LCD works on other motherboard. I can see outputs on monitor and HDMI. what could have caused the problem please help.

Acer aspire 4736z, intel pentium T4200.

 

[jarotech]

Hi, what make and model of laptop do you have, if we don't know how do we help you. It could be simply a coil who is open on the motherboard.

 

[Srijib]

Hi, what make and model of laptop do you have, if we don't know how do we help you. It could be simply a coil who is open on the motherboard.

thanks for your reply, it is Acer Aspire 4736z

 

[jarotech]

You have a coil for the power of the backlight, to be sure this coil is or not the problem, you should read the voltage on pin 40 at the connector for the screen on the motherboard.

 

[Srijib]

I am able to control the backlighting using the function key combination. I doubt if it is the on board gpu but has it been the gpu no display would have work isn't it ?

 

[jarotech]

If you point a light at an angle on the screen, do you see something, do you have a black screen or a white screen?

 

[Srijib]

black screen,

 

[jarotech]

Do you see something if you point a light at an angle on the screen?

 

[Srijib]

Thanks dear, for asking again, I did check before with a flashlight tilted at an angle, the light was brighter than lcd backlight hence was seeing a black screen. In order to double sure I did test again today and also I tried to check the voltage at pin 40, when trying to do so I accidentally discovered some strange thing. When the connector is fixed tight getting black screen. When I pushed one side of the connector out at an angle i.e. pin 1 side it was displaying things. Here is the link showing the connector mode when i get the display.

https://goo.gl/photos/T4nn1eYR681emv429

wondering if this is something to do with the connector, but it should work when it is tightly fixed.

I also has this problem but i was able to get it fixed by tosting the motherboard in Oven

http://www.tomshardware.com/answers/id-3228777/laptop-starting-problem.html