For anyone interested, I posted a simple nRF52 Tx and Rx demo program written in Forth: https://github.com/rabbithat/nRF52_SimpleTxRxDemo
This code is a good starting point for beginners, because it is already working. You can easily modify the code to do whatever transmitting and receiving you want.
@spanners Come to think of it, the particular version of the arduino IDE that you're using might be what's screwing with you. I'm not even sure which ones are the goods ones anymore, and it's partly for that reason that I moved away from it.
Meh, but probably not, since the FORTH hex that you uploaded didn't work. It's probably something else amiss.
@spanners It's a long-shot, but maybe your Jlink programmer is running very old firmware and needs updating? If it's genuine, you should be able to download a current update from the Segger website.
If all else fails, try posting photos of your exact setup. Maybe someone with an eagle eye will spot something amiss.
That said, it sounds like you're very close, and it's just some nit that's holding you back. In that case, just further reducing differences between your setup and the proven setups of others will, by definition, get you over the finish line.
By the way, if you just wanted to simply test whether your module is working at all or not, you could upload this FORTH hex file to it and then see if you are able to communicate to the REPL prompt over the Tx and Rx lines: https://github.com/rabbithat/nRF52840-DK_easy
For the purpose of this test, it doesn't matter that your board is an nRF52832.
The advantage of this particular test is that the hex file is already published, and all you need to do is simply upload it. It won't blink your LED, but you should get working serial communications over pins P0.06 and p0.08. 
@spanners said in First NRF Project (Ebyte nRF52832) device seems to hang after programming:
Crystal Oscillator, Reset:Don't Enable
A small thing, but I'd suggest setting RC oscillator and Reset:Enable
Now to the matters at hand: since you're getting a solid LED light instead of a flashing one, and it's no longer lit if you bulk erase, I agree that it does sound like maybe your pin re-assignments aren't working. To test that theory, see if you are getting a voltage pulse on any of the other pins that would match the expected pulse rate of the LED. You can test for that using a multimeter.
It's so over the top, I couldn't stop laughing: https://www.youtube.com/watch?v=Oij-BdIkPgQ
If you know of another hobby electronics video that's funnier than this one, then please do post a link.
@jeremushka Looks like it might be kinda shakey. Vibration is a notable enemy.
@jeremushka Well, since you ask, you can use a CNC to etch and drill your own PCB: https://forum.mysensors.org/topic/8735/cnc-pcb-milling
A board such as yours would be fairly easy to do that way.
I just now posted a much easier mecrisp-starellis FORTH for the nRF52840-DK: https://github.com/rabbithat/nRF52840-DK_easy/blob/master/README.md
On this one, all you need do is upload the hex file located in that repository and you're done.