First Choice Exit Panic Devices are the same as the Dor-o-matic Panic Exit Devices, and are usually the 1690 or 1790.  First Choice Building Products has the 3690, which is the same as the Doromatic 1690, and the First Choice 3790 is the same as the Doromatic 1790.  The parts are interchangeable between the two companies.  We offer a complete listing of the Doromatic 1690 / 1790 Repair Parts,  and also stock the complete Panics  Doromatic 1690 /1790 Panic Devices.  The most common problem on the First Choice Building Products exit devices are the Doromatic Pinion Gear PB5 and the Doromatic Dogging Assembly PBX-16.   The pinion gear is the gear the actuates the exit device through the key cylinder.  The dogging assembly is the assembly that keeps the latch retracted through business hours.  It is activated by a 7/32″ hex key (dogging key).  On the dogging assembly, the dogging shaft tends to become stripped.  If you have any questions on these exit devices or any other Panic Exit Device, call or email out Panic Exit Device Experts!