Acer TravelMate 4020 Service Manual page 38

Preventive Maintenance
MTTF (Power on hours)
Product Life
32
None
300,000
5 years or 20,000 power
ON hours
None
300,000
5 years or 20,000 power
ON hours
None
300,000
5 years or 20,000 power
ON hours
Chapter 1