Device fails to advertise and has become non-responsive

Hi,

I am using NRF52832 SOC for my application. I have developed application for beacon advertisement based on the nrf sdk. I am facing some issue in device advertisement and even gpio toggling. I have used seeger j-link flash lite application for flashing the binaries. I erase the flash,load the softdevice and then load the application hex file. programming says successfully done but my device is not advertising. I had selected 4000KHz as speed by mistake. i am facing issues in 4 of my devices for which i used 4000Khz clock. Even simple application for gpio toggling doesn't work and SOC chip seems to be non-responsive. The very first time i had flashed, all 4 devices were working fine i.e gpio was toggling, beacon advertisement was working but later it stopped working. Programming succeeds everytime i flash but my application doesn't run at all.

My question is can 4000khz speed setting cause this damage? If yes then is it permanent damage? If no then is there any way to recover from this condition. I repeat, i don't have problem in flashing application on these 4 boards and everytime flashing passes without any problem