Question : Problem: 70W verses 90w Laptop Power supply

I want to clarify someting about laptop power supplies.  I have a Toshiba that uses a 70W power supply.  The power supply died.  I can purchase a 90w that has the 6.30X3.0 MM adapter included.  I know that it will power the laptop.  

The question is the long term effect of using the 90w and the battery life or motherboard damage.

Answer : Problem: 70W verses 90w Laptop Power supply

The 90W is fine.

The number of watts doesn't mean it supplies a constant supply of 90 watts.  It means it is capable of supplying UP TO 90 watts.  If all your machine asks it for is 70 watts, it'll just give it 70 watts.  Totally safe, nothing to worry about.