Asus GL552VW Rev 2.0 don't post.

[J_PH]

Greetings everyone,
I would appreciate your help with the following issue:
I have an Asus G552V notebook, Mainboard model GL552VW Rev 2.0 (Attached images), which upon powering on, does not display any video (Using the HDMI output with an external monitor as well) There is no disk reading, and it does not respond to the keyboard, except for the power button. Only the Power LED and the CAP LED light up.
I have disconnected the battery, disks, and all peripherals to work only with the mainboard and start with the measurements.
The RAM has been checked and is operational (I also replaced it with a working one).
Both the CPU and the GPU heat up during testing, and the fan works correctly.

Here's what I've done:

Visual Inspection: No physically damaged components found.
Voltage = Voltages are checked based on the schematic and the power-on sequence, which appears to be completed. All voltages are present, except +VCCGT.
BIOS = 3 BIOS dumps are performed (BIOS desoldered and reprogrammed, ensuring correct writing). The obtained voltages are as follows:

+1.0V_VCCST = 1.01V
+1.0VSUS = 1.02V
+1.0VSUS_VCCPRIM = 1.0V
+12V = 13.93V
+12VS = 13.92V
+2.5V = 2.5V
+3VA = 3.3V
+3VA_DSW = 3.3V
+3VA_EC = 3.3V
+3VA_RTC = 3.08V
+3VS = 3.36V
+5VA = 5.09V
+5VS = 5.1 V
+FBVDDQ = 1.38V
+NVVDD = 0.9V
+PEX_VDD = 1.03V
+RTCBAT = 0.46V
+VCCCORE = 1.04V
+VCCGT = 0V
+VCCIO = 0.95V
+VCCMPHYG = 1.2V
+VCCPLL_OC = 1.22V
+VCCSA = 1.12V
+VCCSTG = 0.95V
1.2V_PWRGD = 3.3V
AC_BAT_SYS = 19.3V
DDR_VTT_CTRL = 1.22V
DDR4_DRAMRST = 1.22V
DPWROK_EC = 3.3V
IMVP8_PWRGD = 3.3V
ME_AC_PRESENT = 3.3V
PCH_SUSACK# = 3.3V
PM_BATLOW# = 3.3V
PM_PWRBTN# = 3.3V
PM_RSMRST = 3.3V
PM_SLP_SUS# = 3.3V
PS_ON = 3.3V
PWR_SW# = 3.3V
RTCRST# = 3.07V
SUSB_EC# = 3.3V
SUSC_EC# = 3.3V
SUSWARN# = 3.3V
VCCST_PWRGD = 3.3V

I'm feeling a bit disoriented regarding what to continue checking.
Unfortunately, I don't have an oscilloscope to inspect other points.
I've been thinking that it might be a dead CPU.
I would appreciate it, based on your experiences, if you could tell me what else I could check, or if I should declare the equipment for spare parts.
Thank you very much for your time.
I've attached schematics and a boardview.

https://www.badcaps.net/forum/troubl...52vw-schematic

[J_PH]

Greetings to all, I have carried out a couple more tests, thinking that it could be a problem with the LCD backlight. I have obtained the following measurements.


LCD_PWM_CON = 0V
LCD_BACKEN_PCH = 0V
LCD_BACKOFF# = 3.3V
+3VS_LCD = 3.3V


Could it be a chipset fault?

[mon2]

Review this one:

+RTCBAT = 0.46V

[J_PH]

Hello mon2, I have removed the CMOS battery since it is faulty; it has a voltage of 0.1V.
As far as I understand, the equipment can work without any issues without the RTC Battery installed.

Without the battery installed, the voltage of +RCTBAT starts at 0.46V, after 10 minutes it reaches and remains at 1.14V. (I am unsure why the voltage is increasing).
The other voltages are stable:
+3VA = 3.29V
3VA_RTC = 3.07V.

Thank you very much for your help; I will continue checking the equipment.
If there is anything specific to look into, I would appreciate your input.

Best regards,

[mon2]

Check D2001. Remove all power. Meter in diode mode. Measure each diode inside D2001 in diode mode. One direction should conduct and other direction should block.