Laptop screen not turning on/no post

WellThen · March 3

Hey all,

So about a week ago my laptop stopped working outright. When pressing the power button, I got no keyboard back light, no post, no fans spinning etc. Basically all seemed not to work. Today I did some troubleshooting by removing the battery, doing a hard reboot, booting it off of a power adapter, and re-sitting ram. This made the laptop show some signs of life, the laptop now powers on when I click the press button as indicated by the keyboard backlight coming on. Additionally, I can hear the fan spin and the chassis heat up if left on for an extended amount of time. However, I still get nothing on the screen. Even when testing it with another screen.

Any help would be much appreciated. The laptop model is Dell Inspiron Plus 7420

goatedpenguin · March 3

It could be a dead screen and a defective battery.

gurahamu · March 3

Sounds like a MOSFET, the PCH (Platform Controller Hub, which replaced the Northbridge and Southbridge we used to see) or GPU has failed. Cheaper just to get a new laptop rather than getting it fixed as it'll most likely require a new motherboard. Seems to be a common issue in dell/alienware machines, and I see videos regarding problems like this all the time on youtube from repair personnel who try to do repairs involving replacing bad chips rather than replacing motherboards.

The fact that external monitors aren't working either, and it gets hot on the chassis are also a sign that a chip is shorted to ground and is overheating.

If it's under warranty still, definitely send it in.

Edited March 3 by gurahamu
Added some context

WellThen · March 3

1 hour ago, goatedpenguin said:

It could be a dead screen and a defective battery.

hmm, would having booted off of the AC, without battery in the laptop and testing on a different monitor to see if it posts, not eliminate these two possibilities?

goatedpenguin · March 3

If it boots up with monitor then its the screen and if your constantly required to have the laptop plugged in to a power source its a tell tale sign of a dead battery.