Power problem with the XPS 15 9550

[Siegward]

Hey all, 

I've been tearing my hair out with this laptop.  I bought a used Dell XPS 15 9550 from eBay and I cannot get this thing to charge reliably.  The AC adapter has to be plugged in juuuuust right for it to charge and it can take upwards of 20 unplugging and replugging attempts sometimes.  If it isn't just right, I will see the charging indicator come on for a moment and then go out again.  It will power the laptop, but won't charge the battery.  I even purchased another OEM power adapter, but that exhibited the same behavior. 

I have also tried to go the USB-C route.  I bought a cheap 87watt adapter and for the first day it was great and charged it perfectly.  I went to plug it in again and it powers nothing, Windows will make a system tone indicating something has been plugged into the Thunderbolt port and it knows it, but no power.  I tested the adapter on some other usb-c devices, but nothing.  It's dead, and I don't know if it is just a cheap piece of Chinese garbage or if the laptop is somehow to blame for it, or some combination of the two. 

 

I'm about at my wits end. I'm considering putting it back on eBay and selling it at a loss (I don't want to go through Dell's out of warranty process since I've heard nothing good about their servicing). Does anyone have any experience with this machine? 

tl;dr: my laptop won't charge, pls halp