Cisco CP-7841 IP Phone backlight settings not working [closed]

Question

I have a couple of Cisco CP-7841 IP Phones that are working otherwise well, but the backlight controls are not working. I would like to have the backlight off unless the phone is being used (IIRC this was the default setting on older Cisco/Linksys SPA series phones).

The SEP[...].cnf.xml file is configured like this (display related settings only, other omitted):

<device>
  <vendorConfig>
    <daysDisplayNotActive>1,7</daysDisplayNotActive>
    <displayOnTime>08:00</displayOnTime>
    <displayOnDuration>10:00</displayOnDuration>
    <displayIdleTimeout>00:10</displayIdleTimeout>
    <displayOnWhenIncomingCall>1</displayOnWhenIncomingCall>
    <displayRefreshRate>0</displayRefreshRate>
    <daysBacklightNotActive>1,2,3,4,5,6,7</daysBacklightNotActive>
    <backlightOnTime>08:00</backlightOnTime>
    <backlightOnDuration>00:01</backlightOnDuration>
    <backlightIdleTimeout>00:03</backlightIdleTimeout>
    <backlightOnWhenIncomingCall>1</backlightOnWhenIncomingCall>
  </vendorConfig>
</device>

However the settings on the phone display say (the last three do not match):

Active Load: sip78xx.14-2-1-0101-26
Backlight On Time: 08:00
Backlight On Duration: 10:00
Backlight Idle Timeout: 00:10
Days Backlight Not Active: Sunday, Saturday

I think these are the default settings, so something might be wrong with my XML file. I have checked from https://usecallmanager.nz/sepmac-cnf-xml.html that the syntax should be correct.

Any ideas? Thanks!

Answer 1

Hmm, as soon as I posted this question, I noticed the similarities between the "display" settings and the ones applied on the phone - it seems that the "backlight" settings do nothing and the backlight is in fact controlled by the "display" settings.

For example, setting:

<displayIdleTimeout>00:03</displayIdleTimeout>

Results in the phone saying:

Backlight Idle Timeout: 00:03