DSO1202S "System is not shut down properly last time"

japr_padilla@yahoo.com

hand held  oscilloscope dso1200
after use for 12 hours to measure dc voltage with AC power supply, display go black and never return again, when push power button listen sound but after nothing happen.
this machine stay 90 % of the time  keep in the bag and not work, I used 20 times for 20 minutes or less