Hp 1000 backlight problem

[bluestone]

I have this hp1000 6050A2493101-MB-A02 with no backlight. I have got all the voltages at the lvds connector, 19v, 3.3v but still no backlight.
Can anyone point me to where I can locate the Backlight enable pin at the back of the LED screen?

[bluestone]

Re: Hp 1000 backlight problem

Still waiting for an idea

[cyberhack]

Re: Hp 1000 backlight problem

Ok if you dont have schematic then download the data sheet for the led and check.You have 200 posts so your not new to repairs.
Have a look at page 38

[Djosla]

Re: Hp 1000 backlight problem

Pin 22 is enable and should be 3,3v
pin 21 pwm should have 1,5-3,3v it`s brithness control
pins 1,2 should be 3.3v lcd power supply
pins 23,24 should be 19v backlight power supply

[bluestone]

Re: Hp 1000 backlight problem

Thanks cyberhack and Djosla, I already have the schematics of this board and up on checking the connection shown on the schematic on cn503 is not what is on the board.
pin22 which is LCD_BKEN is 3.3v, pin1,2 which is LCDVDD is 3.3 but the 19v backlight power is not at pin 23,24 it is rather at pin 29,30. I have checked different kind of schematics is it is the same configuration.

[cyberhack]

Re: Hp 1000 backlight problem

First is CN503 on the pcb a 30 pin and you have removed the led ie unpluged it
as it will damage with 19 volts going to the led make sure you have the right schematic
i would download the led data sheet .

[bluestone]

Re: Hp 1000 backlight problem

Maybe quanta got all this schematics wrong, the pin 29 and 30 is the 19v Lcd Power, not pin 23,24 as stated in the schematic. I have been able to resolve the problem,
I noticed that there was no voltage at pin21 which is PCH_LCD_PWM, so I realized this voltage is supposed to come from the PCH so I soldered PIN 22 and 21 together and now backlight is on. I just didn't want to reflow the PCH. Thanks to all of you. I hope you can keep it for reference.

[dammysholove]

Re: Hp 1000 backlight problem

it saved me now.. thanks

[ballenian]

Re: Hp 1000 backlight problem

Thanks cyberhack, it saved my day