Hi Frozenice,

Thanks for posting.  Apologies that your computer is not working as expected.

Since it looks like you are off to a good start in troubleshooting your system.  Here are some additional things to try:
  Unplug the AC adapter
  Remove the battery
  Press the power button and hold it for 10-30 seconds
  Replace the battery
  See if the unit turns on without the AC adapter plugged in, then plug in the AC adapter and try it again.

Also try pressing the F12 button as soon as the computer is starting up, run the Diagnostics to check if there is a hardware issue.  Make a note of any error messages and either contact Tech Support for further troubleshooting or post back here.

Hi FrozenIce,

It indicates a memory error If the HDD LED is on, the wireless LED is on and the battery LED is flashing. Please try removing both sticks then trying them one at a time in the bottom slot. If it's still failing, try them one at a time in the top slot. Do you have access to other memory sticks that you know are working?

If it doesn't work with any stick in either slot, it looks like an issue with the motherboard. In this event, the only other thing you can try, is to remove the main battery and mains power, then disconnect the coin-cell battery and hold in the power button for a few seconds, reconnect everything and try again.

Let us know how you get on.

Alright, every combination besides one does not work. This combination was from putting both sticks of RAM back in, and then swapping places with each other, because just putting them back in did not work. It's not turning on still, but it's trying to. The hard drive light is coming on like it does on a normal startup. The other indicator lights do not come on.

EDIT: Removing the CMOS battery, CD drive, and hard drive all failed.

Apologies for the delayed response. From what you have done, it sounds like the motherboard is faulty.

Alright, I found out that this exact thing happened on the exact laptop model before I got my current one. I think the deal was too good to be true, though the current one lasted me from 2013 (or 2014) to now. As long as the motherboard isn't too pricey, I will install it and report back. 

I am facing a s similar issue. Getting this message on running diagnosis

Error code 2000-0142

Validation 7529

Msg: Hard Drive 0-S/N 6WR142MB, self test unsuccessful. Status=79

Hello, I’m your Dell virtual assistant. I see you've opened a thread.

In order for me to review your system configuration, may I have the Service Tag / Express Service Code/ Order Number?

Refer the below link to find the Service Tag:

https://dell.to/2JHuGn1