Hi guys,

I have a 'little' problem with 2 same motherboards.
Motherboards are pulled out from HP G62.
1. 01013y000-388-g
2. 01013y000-600-g
Platform is Quanta AX1
Both mobo's are Intel cpu, Intel HM55 chipset, Ati 216-0774009 graphics.
Problem is when I start the notebook, there is a picture on display, but there is no backlight. LCD cable and display has been changed for test - problem is not in cable or display.
This problem is with both mobo's.
I can't find information which IC turns backlight on when notebook starts - HM55 or Ati. Is there anybody who can explain me boot seq. for this noteobok (I'm a newbie).
You can find schematics here: https://www.dropbox.com/s/teikrnnyb4oef ... REV_1A.pdf

I think to change HM55 at first.

measurements on connector "CN1" pin4, pin38, pin39?

Do not change HM55, better measure the voltage of these signals and pins:
+VIN_BLIGHT on CN1 pin39-40
BLON_CON on CN1 pin 38
VADJ1 on CN1 pin 37
EMU_LID on KBC (U4) pin 31
LID_EC# on KBC pin 127 or CN4 pin 3

and write voltages here

First - thanks for answers.


+VIN_BLIGHT on CN1 pin39-40 - 1.55-1.6v
BLON_CON on CN1 pin 38 - 1.55
VADJ1 on CN1 pin 37 - 0
EMU_LID on KBC (U4) pin 31 - 0
LID_EC# on KBC pin 127 or CN4 pin 3 - here I measure 0.3v and count to 0, which seems strange..

check inductance "L15"
and once more, measurements on connector "CN1" pin4?

I'm sorry for delay, but I have work out of town.
On pin4, CN1 = 0v
But I can't find this L15 on the board...

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QUANTA AX1 - BOARDVIEW

Yes, I found it on the schematic, but I can't find it on the board... Still searching..