Model Asus P2520L
MB P552LA_LJ Rev 2.1 with soldered I3 5010U processor
The laptop charges battery and seem to react to power on, power off, reset regularly, but nothing appears on screen or HDMI or VGA monitor.
Same behaviour when running on battery only, on mains only or on both.
Battery charges fine. RTC battery ok at 3.025V.
When powered on the power on led lits, after a short while the HDD led flashes, but no video. All voltages seem present. ALL_SYSTEM_PWRGD is present, BUFF_PLT_RST# goes high. CPU warms up and fan starts and stop from time to time. Pressing the power button regularly stops the laptop and keeping it pressed for a while regularly resets it ok.
SIO chip replaced and reflashed BIOS with ASUS FW ver 206 and 207 with ME cleaned : same problem.
Tried swapping memory slots and tried different ram stick.
I am looking for suggestions on things to check to solve the problem or to better understand the power on sequence (do you know of any good tutorial ?). It is not clear to me the sequence of events that takes place after the POST and all tensions are present and BUFF_PLT_RST# goes up, when the RAM memory is checked, when the BIOS chip is read, when the IO is adressed, When the video subsystem is initialised, when the boot starts etc
In this case the flash of the HDD led might be a clue?
Thanks in advance
MB P552LA_LJ Rev 2.1 with soldered I3 5010U processor
The laptop charges battery and seem to react to power on, power off, reset regularly, but nothing appears on screen or HDMI or VGA monitor.
Same behaviour when running on battery only, on mains only or on both.
Battery charges fine. RTC battery ok at 3.025V.
When powered on the power on led lits, after a short while the HDD led flashes, but no video. All voltages seem present. ALL_SYSTEM_PWRGD is present, BUFF_PLT_RST# goes high. CPU warms up and fan starts and stop from time to time. Pressing the power button regularly stops the laptop and keeping it pressed for a while regularly resets it ok.
SIO chip replaced and reflashed BIOS with ASUS FW ver 206 and 207 with ME cleaned : same problem.
Tried swapping memory slots and tried different ram stick.
I am looking for suggestions on things to check to solve the problem or to better understand the power on sequence (do you know of any good tutorial ?). It is not clear to me the sequence of events that takes place after the POST and all tensions are present and BUFF_PLT_RST# goes up, when the RAM memory is checked, when the BIOS chip is read, when the IO is adressed, When the video subsystem is initialised, when the boot starts etc
In this case the flash of the HDD led might be a clue?
Thanks in advance
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