Hi,
I totally forgot about the voltage level difference between the debugger and the dongle and connected them. It was somehow working in some cases but not consistenly. While trying to figure out what is happening, I have done a full erase for the dongle. I am now trying to recover. I have followed the instructions in the link https://devzone.nordicsemi.com/nordic/short-range-guides/b/getting-started/posts/nrf52840-dongle-programming-tutorial
Currently the dongle is connected to the debugger with the correct voltage level, I have cut SB2 and shorted SB1 and supplied it via the VDD_OUT pin. I could have uploaded the blinky example. BOARD_PCA10059 is defined and the code calls bsp_board_init().(In the "Build Output" window it says that application is running). However no LEDs are not blinking and the reset button does not work at all.
To enable the USB_DFU again I have downloaded the hex file from https://devzone.nordicsemi.com/cfs-file/__key/communityserver-blogs-components-weblogfiles/00-00-00-00-13/pca10059_5F00_bootloader.zip and tried to upload it using nRFStudio. It has asked me to put device into bootloader mode by resetting it 
. Then listed the possible causes for not being able to upload. So I tried the next option. I have uploaded the open_bootloader example in the dfu folder. However the device still does not work as expected. I also tried to recover it in the programming window of nRF Studio. nRF Connect for Destop does not even see it.
Is it that I have damaged it when connected the debugger or I am doing something wrong with the recovery procedure?
I will be glad if you can please help.
Thanks
