What would cause the Von Duprin 88 series exit device latchbolt not to extend and the crossbar to droop?

The spring in the hinge case or end case assembly lifts the crossbar and both lever arms.  If broken, the crossbar and lever arms will drop down. The weight of the crossbar and levers will automatically retract the latchbolt. Replace the spring and re-set the crossbar by tightening down the wedgetite screws in the proper sequence. Always tighten down the hinge case wedgetite screw first and then tighten down the latchcase or centercase wedgetite screw last. Loosen latchcase wedgetite screw if needed, lift up on latchcase lever arm so that it is equal to the end case lever arm and then tighten down the wedgetite screw. 

DISCLAIMER:

INFORMATION PROVIDED THROUGH THIS SITE IS PROVIDED TO YOU AS IS WITHOUT ANY EXPRESS REPRESENTATIONS OR WARRANTIES OF ANY KIND, AND WE MAKE NO REPRESENTATION OR WARRANTY THAT THIS SITE(OR ANY INFORMATION PROVIDED IN RESPONSE TO YOUR INQUIRY), WILL BE ACCURATE, COMPLETE, OR ERROR-FREE.

YOU AGREE THAT YOU MUST EVALUATE ALL INFORMATION AND RESPONSES, AND THAT YOU BEAR ALL RISKS ASSOCIATED WITH, THE USE OF THIS SITE, INCLUDING ANY RELIANCE ON THE ACCURACY,COMPLETENESS, OR USEFULNESS OF ANY INFORMATION OR MATERIALS MADE AVAILABLE THROUGH THIS SITE.

Other users ask