It is a common issue for CDs to become stuck on a multi stack player unit. Sometimes it is caused by using aftermarket CD media that is slightly thicker than commercial platters, labels that peel off, or just wear and tear after many cycles that causes the internal parts to wear.
When the discs become lodged internally and prevent playing, sometimes recycling power can dislodge them. You can remove and reapply power to the vehicle in an attempt to remove them from the mechanism. Please DO NOT attempt to force a tool into the drive unit to retrieve the discs, this usually does not work and will cause damage to the disc as well as possible damage to other parts of the player.
If the power recycle does not work, the remedy is to either replace the unit or replace the internal parts. Usually, just the fact that the CDs are stuck in the unit means that the thin metal trays and or the spring mechanism is damaged and can no longer be used. And, when retrieving CDs out of the unit, it causes additional damage so it is highly suggested that new parts be installed unless you plan to never use the CD player portion again or don’t mind getting more CD issues in the future.
I can retrieve the discs for you for $30 and replace the entire internal mechanism for $130 plus shipping using NEW OEM parts like the original. If you have interest in my services please use the contact form for more information.