Error 52 T500. A rubber ball was dragged inside the treadmill and got stuck between the front belt roller and the drive motor. Error 52 was generated and every time the treadmill is turned on, Error 52 is displayed.

SOURCE: Hi, have lost the manual for my treadmill York

Error 7 is a Safety Key Error....
That's the red circular magnetic insert that slots into the front of the console...
The manual says : Simply secure the safety key in place and then 
try again..
hope this helps

SOURCE: york t500 treadmill model no:LQ6010 showing err07 when turned on

Error 7 is a Safety Key Error..
that's the red magnetic circular thingy on the console.
Simply secure the safety key in place and try it again

SOURCE: treadmill front roller has a rubber sleever that

That front roller's rubber sleeve by all rights should not be moving any which way. This mean the roller will have to be replaced call iconfitness @1-888-999-3756 and order a new up-graded front roller .