This document explains the meaning of the alarm " PEM not powered " which may arise on FPC member or for the chassis.

Alarm:

user@host> show chassis alarms no-forwarding

2 alarms currently active
Alarm time               Class  Description
2020-02-08 15:07:34 UTC  Minor  FPC 0 PEM 1 is not powered
2020-02-08 15:07:24 UTC  Major  PEM 1 Not Powered

Error in Syslog:

Log>>> craftd[2159]: %DAEMON-4: Receive FX craftd set alarm message: color: 2 class: 100 object: 75 slot: 1 silent: 0 short_reason=FPC 0 PEM 1 No Powe long_reason=FPC 0 PEM 1 is not powered id=167772491 reason=167772160

1. Hardware issue with PEM
2. An issue with circuit breaker/ uncabled PEM/ incorrect voltage 
3. An issue with PEM feed cables
4. An issue with PEM slot

Detailed Logs:

Feb  8 15:07:24   alarmd[3571]: Alarm set: PS SFXPC color=RED, class=CHASSIS, reason=PEM 1 Not Powered
Feb  8 15:07:24   craftd[3572]: Receive FX craftd set alarm message: color: 1 class: 100 object: 75 slot: 1 silent: 0 short_reason=PEM 1 
No Power long_reason=PEM 1 Not Powered id=285213003 reason=285212672
Feb  8 15:07:24   craftd[3572]:  Major alarm set, PEM 1 Not Powered
Feb  8 15:07:29   chassisd[3534]: CHASSISD_SNMP_TRAP10: SNMP trap generated: FRU power off (jnxFruContentsIndex 2, jnxFruL1Index 1, jnxFruL2Index 2,
 jnxFruL3Index 0, jnxFruName Power Supply 1 @ 0/1/*, jnxFruType 7, jnxFruSlot 1, jnxFruOfflineReason 2, jnxFruLastPowerOff 0, jnxFruLastPowerOn 1978275966)
Feb  8 15:07:34   alarmd[3571]: Alarm set: PS SFXPC color=YELLOW, class=CHASSIS, reason=FPC 0 PEM 1 is not powered
Feb  8 15:07:34   craftd[3572]: Receive FX craftd set alarm message: color: 2 class: 100 object: 75 slot: 1 silent: 0 short_reason=FPC 0 PEM 1 
No Powe long_reason=FPC 0 PEM 1 is not powered id=167772491 reason=167772160
Feb  8 15:07:34   craftd[3572]:  Minor alarm set, FPC 0 PEM 1 is not powered

Follow the steps below to overcome the error:

1. Verify the chassis environment:

   user@host> show chassis environment no-forwarding
Class Item                           Status     Measurement
Power FPC 0 Power Supply 0           OK
      FPC 0 Power Supply 1           Present
<snip>

2. Verify if PEM is detected on chassis:

   user@host> show chassis hardware
<snip>
Power Supply 0   REV 04   740-044332   xx       JPSU-650W-AC-AFI
Power Supply 1   REV 04   740-044332   xx       JPSU-650W-AC-AFI
   
   Here, since 2 PEMs are there, verify the minimum number of PEMs necessary for the device/ FPC to stay up. It depends from one device to another. Here, on a QFX5100 device, the power supplies are 1+1 redundant. This means that at a given point in time, 1 power supply must be functioning correctly for the chassis / FPC to remain up and stable.
   
   Since Power Supply 0 is working fine, We can troubleshoot forward with PEM 1 issue. In case the device has a single PEM, the device could go down. In that case, unless a working PEM is inserted, the device would remain down.
   
   As you can see below, the FPC is up since it has one working PEM that can take all the load.
   
   user@host> show chassis fpc detail
Slot 0 information:
  State                               Online
  Total CPU DRAM                 3907 MB
  Total SRAM                        0 MB
  Total SDRAM                       0 MB
  Start time                          2017-07-01 11:19:32 UTC
  Uptime                              952 days, 4 hours, 37 minutes, 51 seconds

   Verify the following:

   • Verify PEM feeds are intact and working fine. You can change feeds and check if PEM alarms vanish.
   • Verify if the Power Supply Unit is functioning properly.
   • Verify if there is any bent pin on the chassis when PEM is housed. An issue on the PEM slot could cause a Power issue.
   • Reseat the PEM
   • Reboot the device
   • If the above does not work, perform a spare test - Replace the PEM with another spare working PEM and check if that comes up without error. If yes, then we can conclude that the issue lies with the PEM. If not, then it is most likely that the issue is with the PEM slot or the feeds.

Contact JTAC Support for replacement or if you get stuck in any step.