i would let the battery die out completely, then recharge it and go in to RCM. Already had that happen with multiple systems and the last one i had it happened with was my psvita on 3.6 enso and i had to let the battery die since i was 2 lazy to take the battery out. When shutting down the vita it would constantly get stuck and the only thing that helped was letting the battery die. Who knows, maybe it'll help