No. It's of no consequence if the V5.20 fw was patched or original. If it's soft-bricked it's because the fw loading was interrupted - likely because the battery failed as the GCD was executed. If the battery is no longer capable of holding a charge there would be a sudden shutoff when you disconnected from PC which was supplying 5V power via USB cable. That's conjecture however if the battery has completely failed electrically it explains why the device seems 'dead'. Because the battery doesn't actually form an essential part of the device's power circuit, it still should power-on even with a dead or missing battery when connected to a suitable 5V power source.