Abstract：The failure phenomena of PB840 ventilator screen displayed “system error”, “hardware alarm, can not determine the air
supply status”, “Ventilator failure, patient parameters cannot be set”, “Cannot set patient, ventilator failure”, “SST is not allowed
and requires maintenance”, and the air compressor does not start after the start and alarm “NO AIR SUPPLY” were analyzed in
this article. Combining the fault phenomenon with the operation principle of the ventilator, we queried the fault log and error
code to locate the faulty part effectively, and then replaced the accessories to repair the ventilator. Importantly, we found that only
by mastering the working principle and self-inquiry function of the machine can we identify faulty components faster, reduce
maintenance time and costs, and better serve the hospital
