Greetings to everyone!
I've experienced a weird issue on my Alienware 18 and I'm hoping it won't take too long to troubleshoot.
The issue is rather easy to explain. The laptop stops charging and enters battery mode without warning all by itself (I didn't unplug the battery adapter and the battery adapter didn't stop working). If I unplug the adapter from the laptop and plug it back in 5 seconds later, the laptop will again work in power adapter mode and the battery will charge. This lasts a few minutes (~3min) and we're back in the battery mode. I have to unplug and plug the adapter back in constantly.
I've started the Dell support assist program and ran a CPU Stress Test. Even though I had to unplug and plug the charger back in several times, the test passed.
I have the latest BIOS. I'm on windows 7. I could normally play games until this issue. Now the battery mode makes it problematic.
Have you ran diagnostics to make sure the adapter and battery are ok? First of all restart the system and at the Dell splash screen start tapping F2. In the BIOS check to make sure the adapter is detected and the battery health is good. Restart again if that looks good and this time tap F12. Run full system diagnostics paying special attention to the battery and adapter. If everything passes try a system reset. Disconnect the battery and unplug the adapter. Now press and hold down the power button for 30 seconds. Then reconnect everything and see if the charging is normal. If none of that helps, then either the DC jack on the laptop is bad (loose pin, not holding the adapter securely), or the problem lies in the motherboard.