My life fitness T3 treadmill stops and gives us a running error or overspeed error please help

SOURCE: error 1 message on older life fitness t3 treadmill

Error 1 - Start up error. This is caused because the belt was commanded to move and the opto (speed sensor on the motor) has not seen any movement or the belts movement was interrupted prior to it reaching its commanded speed. To fix Verify opto operation in Diagnostics, Motor Test
Mode, Section 2. Verify DC voltage at connector P6 pins 1 and 2. Verify that LED 4 on the Motor Controller flashes as the motor moves. Let me know if you need any more help. Fitness Fix-It