Commercial Fixed Wing
Maintenance Airframe; Maintenance Powerplant
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Maintenance
General Maintenance Action
Aircraft; Human Factors; Procedure
Installed new speed brake cable per instruction of work card; the cable needs be routed by hand not pulled using old cable.  I was made aware today that the cable was riding on top of pulley guard.  Cable is routed by hand left without tension until ratio changer is installed; the cable is only visible by mirror on back side of pulley.
Inspected speed brake cable routing and found no discrepancies. I was informed at a later date that one of the cables was found to be routed over a pulley cable guard instead of under the pulley cable guard. The cable is only visible by use of a mirror from the rear of the pulley and moves when the pulley is moved and so it appears to be routed correctly. This was my first time to inspect this cable installation.
Maintenance Personnel reported a speed brake cable was not routed correctly during installation.