Overheating nrf52840

[Sergy]

Hello,

Im using E73-2G4M08S1C module based on nrf52840. Somehow even when in erased state its consuming a lot of energy and starts heating very fast.

Im trying to figure out why and I have a few suspects that need validation:

1) Power is provided at 3.3v via VDD pin. I have forgotten to connect VDH pin, can it be the reason?

2) P0.00 and P0.01 are used as GPIOs

3) Reset pin is used as GPIO

Otherwise I tested everything, there is no shorts anywhere, so not sure what could be wrong.

Any ideas?

Thanks!

[Nguyen Hoan Hoang]

You must have a short somewhere or a bad chip. Try another board to see if you get the same result. 

[Sergy]

Indeed tried a few boards and can't find the short. Can you confirm that disconnected VDDH won't have this kind of effect?

Thing is I can connect to the chip and program it, but at some point it heats up and gets damaged. 

[Nguyen Hoan Hoang]

Looks like you have a gpio configured as output but got shorted to gnd. You can try to find it using a firmware that doesn't enable any gpio at all to see if it has the same problem.  Then one by one enable each gpio until you find it.

[Sergy]

if i use chiperase, id assume it wouldnt set pins as output?

[Nguyen Hoan Hoang]

That is correct.