... - 95%6 Tests:Burn-in test: power supply shall be burn-in for 4 hours under normal input and ... hardwood with the thickness of 20mm,and the hardwood shall be put on the base of the cement ... secondary add 500Vdc test voltage7 MTBF Qualifications: The MTBF shall be at least 50,000 hours at 25°C, ... the output rail short, the power supply shall not damage, and shall be self-recovery when the fault condition is ...