Dhcp server not issuing ip address

hi, I am using win2k3 server and i am using that server as a dhcp and license server and i got a problem that suddenly it stopped to issue ip address tomy clients and earlier it was worked well and i tried by uninstall scope and reinstalllscope and even i am getting any error in this scope and in event viewer and i tried uninstall the dhcp and reinstalled and assign new scope but still its not working .But i am able to ping and able to reach the server by using ip and host address.And now i am using other server as a dhcp its working well, that only for temporarily so kindly give me some suggestion to shortout this issue.