laptop shutting off randomly when in AC power

[gabfajardo24]

Hi
I have a Dell 14R Inspiron 5437
Processor: Intel Core i5-4200U 1.60Ghz
RAM: 4GB
GPU: Intel HD Graphics / NVIDIA GeForce GT 740M
OS: Win 8.1 Pro


It shuts down randomly(like a sudden power off) when in ACpower playing games or using heavy programs, and rarely when surfing, so it's really random but works fine in battery or battery and plugged (doesn't shut, not even once). I had a hardware replacement (MOBO and Fan), but that doesn't cure the problem. I already reformatted the system and it's still there. Temperature is fine. I now have no idea of what i should do next to fix the problem. can somebody help me please.
thanks in advance.


NOTE: and if it shuts, the power button will not work to turn it ON until i unplug the power cord from the laptop and connect it again.

 

[TechyInAZ]

Make sure your BIOS and drivers are up to date.

 

[gabfajardo24]

i downloaded the latest bios offered by dell and it says that i already have that one installed.

 

[TechyInAZ]

I think it's another hardware problem then. Your AC power brick is dying most likely.