IMF (Internal Media Frame) will not release upon command from console. Fixture goes through the attempt but the wings do not release from the magnet and re-close when the lens train moves back.
Check to make sure there is no adhesive residue on the retention magnet. Early versions had a Velcro dot to reduce noise, heat softened the glue and the dot dislodged, leaving a sticky residue which interferes with the process. An alcohol wipe should clean off magnet and metal gel frame. Then test the operation.
Failing that examine the position of the optical rail on the drive side of the assembly. The forward clamp should be positioned so the front edge of the clamp is angled just to the edge of the chamber on the end of the optical rail. This allows the clamp to be across the full diameter of the rail, but also allows the shuttle to travel all the way forward. If the clamp is perpendicular, the shuttle will stop prematurely, preventing the wings from opening. If this is suspect re-position the clamp. After re-positioning, test the operation.
If this is correct inspect the springs. A broken spring can reduce the opening force enough to prevent the wings from opening especially on the drive side. If broken, replace springs and test the operation.
If the springs are intact, take a small screwdriver/pick/ pen what have you and move the edge of the spring that rests in the cavity of the lens assembly, and re-position it so it is on top of the edge of the lens on all four springs. This applies a little extra force to the spring tension. Test the operation again and if it works, the springs should be replaced as they may have weakened or have been marginal at the start.