N1548P Poe not working with old Cisco IP Phones

Hi all:

I am facing a problem with a N1548P and old Cisco IP phones (such as CP-7940 and CP-7960). Phones can't be turned on with PoE, however, other phones like Cisco CP-3905 don´t have any problem.

I just did the update to the latest firmware, but the problem persists.

Dell_Santa_Lucia#show version

Machine Description............... Dell EMC Networking Switch
System Model ID................... N1548P
Machine Type...................... Dell EMC Networking N1548P
Serial Number..................... CN0FDH812829858H0382A01
Manufacturer...................... 0xbc00
Burned In MAC Address............. F8B1.568E.9540
System Object ID.................. 1.3.6.1.4.1.674.10895.3066
SOC Version....................... BCM56150_A0
HW Version........................ 2
CPLD Version...................... 16
Image File........................ N1500v6.5.3.3
Software Capability............... Stack Limit = 4, VLAN Limit = 512

unit active backup current-active next-active
---- ----------- ----------- -------------- --------------
1 6.5.3.3    6.3.2.4     6.5.3.3       6.5.3.3

 

I also checked the power inline firmware and it seems that it is fine.

Dell_Santa_Lucia#show power inline firmware-version

Unit Firmware Version
---- ----------------
1 211_3

 

When I entered the command "show power online", I noticed several strange things like: all ports are in "Test-Fail" state, there is no value in "Total Power" or "Threshold Power".

Dell_Santa_Lucia#show power inline

Unit Status
===========

Unit........................................... 1
Power.......................................... On
Total Power.................................... 0 Watts
Threshold Power................................ 0 Watts
Consumed Power................................. 0 Watts
Usage Threshold................................ 90%
Power Management Mode.......................... Dynamic
Power Detection Mode........................... dot3at+legacy

Port Configuration
==================

Port Powered Device State Priority Status Class Power[mW]
--------- ------------------------ ----- -------- ---------- ------- ---------
Gi1/0/1 auto Low Test-Fail Unknown
Gi1/0/2 auto Low Test-Fail Unknown
Gi1/0/3 auto Low Test-Fail Unknown
Gi1/0/4 auto Low Test-Fail Unknown
Gi1/0/5 auto Low Test-Fail Unknown
Gi1/0/6 auto Low Test-Fail Unknown
Gi1/0/7 auto Low Test-Fail Unknown
Gi1/0/8 auto Low Test-Fail Unknown
Gi1/0/9 auto Low Test-Fail Unknown

I also tried modifying the "Power Management Mode" and the "Energy Detection Mode", but nothing happens.

 

The LLDP configuration is by default

 Dell_Santa_Lucia#show lldp interface all

LLDP Interface Configuration

Interface Link Transmit Receive Notify TLVs
--------- ------ -------- -------- -------- -------------
Gi1/0/1 Up Enabled Enabled Disabled 0,1,4
Gi1/0/2 Up Enabled Enabled Disabled 0,1,4
Gi1/0/3 Up Enabled Enabled Disabled 0,1,4
Gi1/0/4 Up Enabled Enabled Disabled 0,1,4
Gi1/0/5 Up Enabled Enabled Disabled 0,1,4
Gi1/0/6 Up Enabled Enabled Disabled 0,1,4
Gi1/0/7 Up Enabled Enabled Disabled 0,1,4
Gi1/0/8 Up Enabled Enabled Disabled 0,1,4
Gi1/0/9 Down Enabled Enabled Disabled 0,1,4
Gi1/0/10 Down Enabled Enabled Disabled 0,1,4
Gi1/0/11 Down Enabled Enabled Disabled 0,1,4

Dell_Santa_Lucia#show lldp remote-device all

LLDP Remote Device Summary

Local
Interface RemID Chassis ID Port ID System Name
--------- ------- ------------------- ----------------- -----------------
Gi1/0/1 6 172.22.122.246 cc9891d1fc9b:P1 SEPcc9891d1fc9...
Gi1/0/5 8 172.22.122.254 38ed18e87773:P1 SEP38ed18e87773
Gi1/0/6 9 172.22.122.220 B4A4E3D6CB9D:P1 SEPB4A4E3D6CB9...
Gi1/0/8 7 172.22.122.214 00425ac6b7ad:P1 SEP00425ac6b7a...
Gi1/0/48 5 00:16:46:54:AC:00 Fa0/23 OMM_INAP.uchile.cl