Cisco 7975 expansion module not lighting up

[coffee.guy]

Hi,

I have a client with a few Cisco 7916-24 expansion modules on their 7975 phones. One of the users modules is working fine and lighting up - we can see the users speed dial numbers and watched lines OK. However The other 7975 expansion module is not lighting up at all.

See below for the ephone's config;

ephone  31
 device-security-mode none
 mac-address 58BC.2775.F9F5
 ephone-template 16
 max-calls-per-button 2
 username "user" password <>
 speed-dial 1 0000000000 label "Mobile 1"
 speed-dial 2 0000000000 label "Mobile 2"
 speed-dial 3 0000000000 label "Mobile 3"
 speed-dial 4 0000000000 label "Mobile 4"
 type 7975 addon 1 7916-24
 button  1:35 2w42 3w44 4w45
 button  6w17 7w48 8w8 9w43
 button  10w14 11w15 12w50 13w49
 button  14w16 15w7

They are using CME version 7.1

IOS: uc500-advipservicesk9-mz.124-22.YB8.bin

Hardware: UC520

[Leo Salcie Tejeda]

Hi,

Did you try switching both expansion module? Maybe the one it doesn't light up is simple broken.

Regards

[Jonathan Schulenberg]

You need an AC/DC power supply to support two expansion modules. The phone needs more than 802.af PoE is capable of providing. Part number is cp-pwr-cube-3.

[Mohammed al Baqari]

Hi,

How are you powering the second expansion module. You need either to connect to second power supply or connect both modules back to back using Aux ports.