Laptop keeps going to sleep

Shradul,

https://www.dell.com/community/Laptops-General/Dell-Latitude-E5550-randomly-going-to-sleep/td-p/4722650

this maybe the cause

Magnetic wristband on the right wrist will trigger the sensor into thinking the lid is closed.

This is correct.  We have brand new Latitudes that are having the same issue.  In our case a user was wearing her FitBit with a magnetic clasp.  This caused the screen to turn off every time she moved her hand over the bottom right hand of the laptop. 

This thing was driving me nuts!!!

Did a factory reset and reinstalled 1803 after a 1903 upgrade, thinking 1903 was the issue.

Used process monitor and realized WUDFHOST.EXE was putting the computer to sleep. Couldn´t find  a root cause.

Renamed wudfhost.exe to wudfhost.exe.old... had some issues doing this.

Finally.. I found your comment!

It was a magnetic wristband.

Thank you, thank you, thank you! 

Magnetic wristband, DUH! Why didn't I realize that?

I think this was my problem. It hasn't happened again since I took my watch off. It has a magnetic wristband.

Thanks for the easy solution!

I'm not 100% sure this was my own problem, because the computer would go to sleep randomly after I walk away, and because I don't use magnetic jewelry.  Nonetheless, just on the off chance that this really is the problem (perhaps something is wrong with my lid sensor?), I took the following additional steps:  I also edited the power plan to "Do nothing" if I lower the lid, and to "do nothing" if I hit the sleep button.  In other words, I think I may have covered every conceivable situation where sleep mode could be invoked.  Keeping fingers crossed!  --Sandy 

I came to this thread because of the same issues but I don't wear any magnetic jewelry either. I think what is happening in my case is that I occasionally place my iPhone next to the trackpad for my laptop and there is something either in the phone itself or the case for my phone that is triggering sleep mode for my laptop. I don't know if it is a magnet or some kind of signal, but it seems to cause my laptop to go to sleep mode pretty consistently if I place my phone directly on top of any part of it.

With me it was not because of some magnetic wrist band etc... it is happening anytime - me sitting and working on laptop or not doing anything and laying in bed and it just goes to sleep mode - all off and just flashing side lights on keyboard meaning it can be switched on again by pressing button for power up. And sometimes it happens 3 times in a row - it goes by itself to sleep, then in couple minutes wakes up by itself and then again goes to sleep.... and I was thinking like someone is waking this machine up or putting it into sleep on network/lan lol. It is just weird. All settings are put computer to sleep NEVER but it still does. Not sure why or what is the solution.

For at least the Dell Latitude 7410, disable the proximity setting in Dell Optimizer.

The 'walk away" mode uses the camera even it is blocked or staring into empty space.

Did you find a solution afterall? I am having the same problem now. Using a dell dock with the lid closed. This was not happening last week.

It's the Proximity Sensor! (and super hidden)

In your search bar type Dell Optimizer, then scroll down to Proximity Sensor & disable it. Here is a link if needed: https://www.dell.com/support/kbdoc/en-us/000130242/proximity-sensors-and-walk-away-lock-functionality-may-report-the-system-locking-to-quickly 

I have the same problem as well.