What exactly do you mean as “now”? At which exact moment it refused to arm? After you changed LOG_BITMASK value? After you reproduced issue and it got captured in log file? After you removed sd card from pixhawk?
In case you have solid red LED check pls if you forgot to insert sd card back to pixhawk?
So far I can see in your log file it seems you have problem with pixhawk powering from power module. It should has Vcc voltage value from 5.0V to 5.2V. As you can see your actual Vcc is about 4.7V which is not enough:
What kind of power module you are using? You need to measure a voltage on Vcc line from power module to pixhawk by multimeter. It should be about 5.3V. Here is pixhawk power connector pinout:
