ASUS GU502LW Booting Issues and Wi-Fi/Bluetooth Failures – Need Help

Hi @izihirweeloi

Won't turn on i.e. won't pass POST (Power On Self Test) or passes POST and won't boot into the OS, there is a difference?

To see if it passes POST check if you can get into BIOS OK every time you start the laptop?

If it passes POST and you're in BIOS, check if the HDD (or SSD) is shown as being detected by BIOS and if it does then check if it boots OK from that point when you exit BIOS.

If it doesn't get to the OS desktop it may be a problem with the HDD or the OS boot partition files.

Process of elimination.

You have to work out what is working every the time at startup and what isn't and then if it isn't working find out why it isn't, e.g. if it passes POST and the HDD is being detected every time on startup but it intermittently doesn't boot into the OS run programs to check the HDD or the OS startup files or if it passes POST but the HDD is missing in BIOS, check the HDD connection etc

As for the WiFi/BT problem, download, install and run this free WiFi sniffer program and use it to check the signal strength of the WiFi network that you're connected to. When the WiFi drops out check the signal strength of the network. If it is too low i.e. > -80dBm, it may be due to an antenna problem in the laptop, which could be a faulty WLAN antenna connection or perhaps the antenna is damaged where it passes through the hinge between the motherboard and the lid of the laptop.

BT uses the same antenna and the same WLAN card as the WiFi so it may be why both are affected

Just things that I'd try to narrow down what's happening.

Hi @izihirweeloi

Try a full power refresh and check if that resolves the startup problem so that it passes POST and that you can get into BIOS.

Disconnect the charger from the laptop (if connected) and then open the laptop and disconnect the battery from the motherboard i.e. just unplug the battery cable from the board.

Here's a teardown video that may help. The battery cable can be seen being disconnected from the board, starting from 1:56 minutes into the video.

Press and hold the laptop's Power button for a full 30 seconds and then release it.

Reconnect the battery cable to the motherboard, reassemble the laptop, connect the charger and check if it turns on and passes POST.

If it does, there may be a message stating that the date and time are incorrect. This is normal as the BIOS has been reset back to factory default by the above procedure. Once the date and time have been corrected, the message won't appear the next time the laptop is started. Also any user definable BIOS settings that were changed by you, to suit whatever operating requirement you needed, will have to be changed back again as well.