What was found
DEN - ON FLIGHT 4303, RETURNED TO GATE, HYDRAULIC 1B, 2B, 3B PUMP CAUTION MESSAGE WHEN FLAPS LOWERED. MAINTENANCE FOUND HYDRAULIC PUMP BREAKERS FOR ACUP 1B, 2B, 3B'S POPPED. RESET BREAKERS AND RECREATED SITUATION AT DEICING PAD AND LOWERED FLAPS AND RAISED THEM. NO C/B'S POPPED, FLAPS APPEARED NORMALLY. HYDRAULIC PUMPS OPERATED NORMALLY WITH C/B'S STAYING RESET. NO OTHER FAULTS OR DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.