PPK2 cant work

Question

After upgrading the software, it cannot work. How can I restore it to the previous state 
 the product is PPK2

SwRa · Answer

Hi Jerry, 
 Could you try the following.? 
 Disconnect all other Nordic devices from the computer, turn off the kit and remove it from the plastic by removing the four screws. Insert USB to J2 (USB DATA/POWER). Short a connection between GND (e.g on the four pin power output header) to TP34 on the PPK2. While holding the jumper cable, turn the kit on and remove the jumper. Now the PPK2 should be in bootloader again. 
 Open the PPK app, and select the device which is now just a serial number. 
 When selecting it, the user will be prompted to program the application and it should now be working again. 
 
 Best Regards, 
 Swathy