When you see the POST Code value reach 0 (zero), it means that BIOS POST operations have completed successfully and the BIOS is transitioning into the boot process. A hang at this point means that there is a problem with the boot image and/or the boot device and/or motherboard components (like memory)
As Al asked, what changed? What did you do just prior to the problem occurring for the first time? What O/S is the board trying to boot? Please answer all of the other questions asked.