What causes a turbo to go bad

[Needsoles]

i'm wondering what causes a turbo to go bad? when i put my turbo in 1300 miles ago it was fine but now it has shaft play like a mofo

 

[Needsoles]

Have you Tested the ISC?

not yet. how do you test it?

 

[MY1GDSM]

not yet. how do you test it?

http://www.austarion.com/tech/4g63.pdf

Its a 3.57mb .PDF

Its on Page 52 -------Idle air/Speed control motor (stepper motor) Operational Check

 

[Needsoles]

i think it blew up today

 

[Needsoles]

my turbo has made a weird noise during boost and i have noticed a loss in power. so today it doesn't feel like it its sppoling i don't hear it spool up and it defiantly has not as much power

 

[SpyderDSM]

what kind of noise? you're sure its the turbo and its not the engine misfiring or anything?