DB Drive A3 80.4 Amp Problems

Hi guys this is my first time posting, and I hope you can help me. I recently have been working on a sound system on an Isuzu Pickup. The door speakers where replaced with Focal and wired to the head unit Pioneer AVH 4300. The rear speakers are component 6.5" model 165AS(4ohm) and the front are 6x9 model 690AC(4ohm) and a pair of kicker tweeters with their independent crossover (4ohm). I purchased a DB Drive A3 80.4 4 channel amp and wired it up. I powered on the system and was in the middle of tweaking the gain when the amp shut off. It burned both the 20 amp fuses, and when I try to replace them it burns them immediately (with or without remote signal). I have checked the wiring, nothing is shorting to ground and the speakers are fine. The only conclusion I can come to is that the 2 ohm load(after the placing the front 6x9s and tweeters in parallel) mixed with the 4 ohm load from the rear caused the amp to die. The amp manual says it can handle a 2 ohm load but I assume it only works if all 4 channels have the same load. Do you guys have any idea? From other threads I read a bad amp is a possibility. Thanks in advance.Technumber1

The power supply in your amplifier has failed. Different ohm loads on each channel will not cause this failure, unless 1 or more of the channels are wired below 2 ohms.