About 10 second upon start-up, the Cybex 520T Treadmill would abruptly stop and display in the consul is an Err3. We transferred the speed sensor of the unit to another Cybex treadmill and initially the Err3 was repeated but then after increasing the distance of the sensor with the flywheel target, the Err3 did not re-occur anymore. So right now, we are just confirming what is the equivalent of Err3 and what exactly are the parts that needs to be replaced in this case.

SOURCE: My Cybex 520T is comming up with Error 9 on the Screen

Hi, Error code 9 on your treadmill means the brushes on the motor need replacing. This is an automatic indication that is set for 100 miles of use to prevent damage to the motor. Replace both sets of brushes and this should Fixya!

SOURCE: Need to download manual for cybex 530t treadmill. Can't find link

replace the console, you buy that part individually

SOURCE: re: model cx455T cybex treadmill.

hi,

Every 9,000 miles (14,500 km) the unit will show "SVC" on the display. This will continue until the service is performed and the service odometer is reset.
1. Determine mileage.
A. While in Dormant Mode enter Test Mode by pressing and holding the Heart Rate and Level keys simultaneously for five seconds.
B. Press the Dist key. DIST appears on the display. Record Mileage. NOTE: Once the unit exceeds 999 miles or kilometers the odometer will use both screens. Example:
12,805 miles or km would be displayed as 12 805 . NOTE: To exit Test Mode, press the Pause/Stop key .
Every 5,000 miles (8,000 km).
? Check running belt tension and tracking.
? Move treadmill and vacuum underneath..
? Lubricate elevation pivot points.
(Watch the videos for tentioning and lubricating treadmill belt.)