Hello Alex,
When you remove the LCB out the back of the ML6000 you only need to pull it out about 2-3 inches. Now since you did that & didn’t get any RAS tickets on the ML when you removed the LCB what you can now is to pull out the CF card on the LCB and put the LCB back into the ML and let it boot. You will get some errors on the front screen don’t worry about them as they will be stating that the CF card is missing. Let it attempt to boot up for about 5-10 minutes. Once that is done then power off the ML and reinsert the CF card and let it boot. Once the ML has booted then check to make sure that there are no open RAS tickets and if not any then try to flash the firmware again.
Please let us know if you have any other questions.