Hey guys, I need some help with troubleshooting a laptop.
Motherboard: ASUS GL552GX rev2.0
Issue:
- Turning on but no display and no drive activity.
- Fan starts slow then goes to full power. (It does throttle at time.)
- Laptop turns off after a 30sec to 1min.
Power draw:
Power supply set to 19.7V
Off state: fluctuates between 9 to 12mA
On state: around 1.6A
Measurements:
- Check for any shorts -> none found
- Check voltage rails (all main rails present):
VCore: 1.77V
VGpu: 0.9V
RAM: 1.35V
Solid 3.3V & 5V always
Other measurements:
OFF State:
BUF_PLT_RST#: 0V
H_DRAM_PWRGD: 0V
H_CPUPWRGD: 0V
ON State:
BUF_PLT_RST#: 3.3V
H_DRAM_PWRGD: 3.3V
H_CPUPWRGD: 1.2V
RTCRST#: 3.3V (Both is ON or OFF state)
All steady voltage levels
Clock:
Stable 32.768KHz both in on and off state
Stable 25MHz in ON state
Here is where things get weird:
- Probing with Oscilloscope. (Laptop in OFF state)
-> Constant 5.53Hz on all BIOS pins except ground
-> Constant 5.53Hz on PM_RSMRST#, ME_SUSPWRDNACK,
ME_ACPRESENT (but inverted waveform).
- Probing with Oscilloscope. (Laptop in ON state)
-> All lines that were at 5.53Hz are now solid 3.3V
-> No data transfer observed on BIOS pins. (data lines go straight to 3.3V from
5.53Hz upon pressing power button.
Other observation
- When HDD is connected to motherboard, there is no activity and LED stays solid ON and drive does not spin up (Voltage at connector is present)
HDD was tested independently and works without issue.
What I have done so far with no luck
1. Flash BIOS from another dump -> No luck, still 5.53Hz
2. Replaced BIOS chip
3. Replaced EC and flash from another dump.
4. Erase EC and let device reflash EC (tried with both Original and downloaded BIOS)
Although there is no backlight, screen can be seen going dark when laptop is turned on and changes back to a lighter color when powered down.
Further info will be added if anything was missed. Am I correct in thinking its potentially a bad PCH? Or is it just a weird BIOS issue. I am unable to find a schematic for this motherboard and only managed to find a repair guide and boardview for what was listed as rev1.0 (although it also seem to match rev2.0).Relevant documents/files & bios dumps are attached.
******************************
MOD EDIT: Bios + EC moved to a new thread: https://www.badcaps.net/forum/showthread.php?p=982393
Motherboard: ASUS GL552GX rev2.0
Issue:
- Turning on but no display and no drive activity.
- Fan starts slow then goes to full power. (It does throttle at time.)
- Laptop turns off after a 30sec to 1min.
Power draw:
Power supply set to 19.7V
Off state: fluctuates between 9 to 12mA
On state: around 1.6A
Measurements:
- Check for any shorts -> none found
- Check voltage rails (all main rails present):
VCore: 1.77V
VGpu: 0.9V
RAM: 1.35V
Solid 3.3V & 5V always
Other measurements:
OFF State:
BUF_PLT_RST#: 0V
H_DRAM_PWRGD: 0V
H_CPUPWRGD: 0V
ON State:
BUF_PLT_RST#: 3.3V
H_DRAM_PWRGD: 3.3V
H_CPUPWRGD: 1.2V
RTCRST#: 3.3V (Both is ON or OFF state)
All steady voltage levels
Clock:
Stable 32.768KHz both in on and off state
Stable 25MHz in ON state
Here is where things get weird:
- Probing with Oscilloscope. (Laptop in OFF state)
-> Constant 5.53Hz on all BIOS pins except ground
-> Constant 5.53Hz on PM_RSMRST#, ME_SUSPWRDNACK,
ME_ACPRESENT (but inverted waveform).
- Probing with Oscilloscope. (Laptop in ON state)
-> All lines that were at 5.53Hz are now solid 3.3V
-> No data transfer observed on BIOS pins. (data lines go straight to 3.3V from
5.53Hz upon pressing power button.
Other observation
- When HDD is connected to motherboard, there is no activity and LED stays solid ON and drive does not spin up (Voltage at connector is present)
HDD was tested independently and works without issue.
What I have done so far with no luck
1. Flash BIOS from another dump -> No luck, still 5.53Hz
2. Replaced BIOS chip
3. Replaced EC and flash from another dump.
4. Erase EC and let device reflash EC (tried with both Original and downloaded BIOS)
Although there is no backlight, screen can be seen going dark when laptop is turned on and changes back to a lighter color when powered down.
Further info will be added if anything was missed. Am I correct in thinking its potentially a bad PCH? Or is it just a weird BIOS issue. I am unable to find a schematic for this motherboard and only managed to find a repair guide and boardview for what was listed as rev1.0 (although it also seem to match rev2.0).Relevant documents/files & bios dumps are attached.
******************************
MOD EDIT: Bios + EC moved to a new thread: https://www.badcaps.net/forum/showthread.php?p=982393
Comment