Cisco Phones Not Receiving IP Address with GS748TP

[Myllz]

I have kind of an odd problem. We currently have a few different models of Cisco VoIP phones in our building and none of them seem to be able to receive an IP address from our new GS748TP switch. PoE works fine and the phones receive power, but they will not get an IP address. Even without going through PoE and using a power brick, they still won't get an IP address. The strange thing is I have a JGS524 and a FS526T switch that they'll get an IP address from just fine. All three switches are getting their uplink from the same place.

Is there a default setting or something on the GS748TP that needs to be changed that isn't on the other two switches?

[adit]

Is the switch programmed?

[Myllz]

I guess it depends on what you mean by programmed. It has an IP address on the network and is pointing to the correct gateway, etc. Windows clients plugged into it get an IP address no problem and function normally. For whatever reason it's just the Cisco phones that won't get an address. Other than naming it and giving it an IP address it's pretty much right out of the box (minus upgrading the firmware).

[adit]

Default the switch and test.

[Myllz]

Did a factory reset, same result.

[Myllz]

Figured it out. The phones were set to operate on VLAN 100. Added VLAN 100 to the switch and tagged the ports, now they connect.