Unknown USB Device (Device Descriptor Request Failed) - Win 10 I am posting a possible solution here for any online searches happening upon this exact issue.

So I have a third party board (Mega 2560) and I was plagued with my board intermittently working, on some rare occasions it worked but in most cases it just threw me the "USB device not recognized" after plugging it into my pc.

Upon closer inspection I have noticed the following

The one coupling capacitor (Blocks DC but allows AC and signal to pass) was poorly soldered, barely making contact!

So if your pc intermittently connects to your arduino, maybe check what the physical signal path looks like, you might find something like this.
SMD soldering is not easy but here is the fix. Continuity achieved!