hp folio 9470m 6050A2569401-MB-A01 no display

[Zilicon]

Please, help.

The above motherboard turned on but no display. The PC posted because I could hear the sound when a USB device was connected to the PC.

However, I noticed that the capslock did not glow when pressed from the PC's keyboard but it only glows when it is pressed from an external keyboard.

I noticed the enable of U3000 is 0v.

U3000 readings:
1 output - 0v (P3V3S_LCDVDD)
2 GND- 0
3 EN- 0 (LVDS_VDD_EN)
4 dis- 0
5 in- 3.3v

I bridged 5 and 1, the screen became darker but no backlight. I couldn't find a way to power the backlight.

L_BKLT_EN too is 0v same as LVDS_VDD_EN

both enable signal for image and backlight came from U4701 both are 0v.

I have reprogrammed the BIOS chip, but the result remains the same.

please what can I do next?

there is no short on the board and the screen works on another PC

attached are images of u4701and u3000

[mon2]

Test with an external monitor. Does this work?

https://h30434.www3.hp.com/t5/Notebo...p/td-p/6799386

[mcplslg123]

Check D3000 pin3 and 1 for voltage.

[Zilicon]

Thanks mon2, I'll update you on this

[Zilicon]

Check D3000 pin3 and 1 for voltage.

Thanks. 0v at both pins

[Zilicon]

Thanks mon2, I'll update you on this

Confirmed.
it displayed to an external monitor

[mcplslg123]

Remove the LID Switch and try again.

[Zilicon]

Remove the LID Switch and try again.

It uses on-board LID switch

[mcplslg123]

It uses on-board LID switch

What do you mean by that? LID SWitch cant be desoldered?

[Zilicon]

What do you mean by that? LID SWitch cant be desoldered?

I meant the power switch is on board- not detachable.

I will say THANK YOU 😊 VERY MUCH. The mention of LID switch gave me a hint. So I dug deeper into what LID switch is. Initially I thought it qas just another name for the power switch, but I got to know it's function after I dug deeper.

In summary, the LID switch was at fault (U9013) can be found around "mute" button (top left) aread of the MOBO.

so i bridged the in and out pin, and VOILA! IT WORKED!.

thank you once again.