back light problem on my acer es1-511

[Akhilesh_5]

my backlight has stop working can you help ???????????

 

[Akhilesh_5]

no voltage

 

[jarotech]

Did you verify the voltages on U11 with the laptop powered? Meaning you still have 16 volts on pin 1 of the LCD connector.

 

[Akhilesh_5]

i do have 16 volt in pin 1

 

[jarotech]

If you have no voltage at pin 5 on the U11 chip, this means that the chip is not receiving the 3 volts switched. Measure the voltage at pin 4 and 5 on the U10 chip, it's just beside the LCD connector. The pins number is the same has U11. You are very patient with my requests.

 

[Akhilesh_5]

it gets 3.34 volt on pin 4 5

 

[jarotech]

You have the 3.3VS on the U10 chip, but you don't have the 3.3VS on the U11 chip, the U11 chip controls the backlight off when the output on pin 4 is 0 volts. So, you need to find why you don't have 3.3VS on pin 5 of the U11 chip.

 

[Akhilesh_5]

i have 3.30 volt in pin 5 and pin 1 but no voltage in pin 3 2 4

 

[jarotech]

 

[Akhilesh_5]

i have found the problem its the track of lcd connector pin5 that has been damaged it doesnt go on pin 4 of u11 chip

does u11 and u10 chip linked together???

 

[Akhilesh_5]

i cant add an photo on the forum

 

[rgd1101]

i cant add an photo on the forum

read http://www.tomsguide.com/forum/id-2299675/read-forum-rules-styling-posts.html
under "Styling Posts & Adding Images"

 

[jarotech]

No, U10 is for the LCD power, U11 is for the control of the backlight ON or OFF. But from the schematic I have, the pin 4 of U11 is connected to pin 7 and not 5 of the LCD connector.

 

[Akhilesh_5]

 

[Akhilesh_5]

can you give a solution what can i do??

 

[Akhilesh_5]

[image]http://imgur.com/UIOuqbq[image]

 

[jarotech]

If you have 3.3 volts on pins 1 and 5, and 0 volt on pins 2 and 4 for the U11 chip. This is the reason the backlight is OFF, you need 3.3 volts on pin 4 for the backlight to be ON. Right now the pin 2 is controlling the output for the U11. Pin 2 for the U11 is connected to the EC chip, so, what is controlling the EC to give 0 volt to pin 2 for the U11? This is why I asked to verify the voltages for the U14 chip.

 

[Akhilesh_5]

its has worked now thank you for all your explanation