As a book end to anyone else who finds this thread, Juniper has issued a KB article not to upgrade the PoE controller manually, but to instead let it be upgraded as part of standard JUNOS upgrades.
https://supportportal.juniper.net/s/article/PoE-firmware-upgrade-may-lead-to-loss-of-PoE-functionality
If you have already upgraded your controller and it is borked, contact JTAC for assistance. If you don't have a support contract, you may be able to fix it by performing a USB format install.
https://supportportal.juniper.net/s/article/EX-How-to-format-install-EX2300s-and-EX3400s-via-USB?language=en_US
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MATT MORRIS
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Original Message:
Sent: 01-01-2023 10:26
From: fb35523
Subject: POE Controller Failure After Attempted Upgrade
In case someone has this problem on an EX2300-24P, I can tell you it works there too! I'm on 21.2R3-S2 and the PoC controller in fpc1 failed as I was upgrading it from master fpc0. Reboot didn't help, but the procedure above did the trick.
request system firmware upgrade poe fpc-slot 1 file /usr/libdata/poe_latest.s19
Note: the extension "file /usr/libdata/poe_latest.s19" is a hidden command so you need to copy and paste that or type it in as it is. Expanding the keyword "file" will not work either.
The file /usr/libdata/poe_latest.s19 points to /packages/mnt/jpfe-EX34xx/... so I was a bit worried at first if this was for the 3400 only, but it only took a minute and then all was fine! Thanks Pradeep!
Original Message:
Sent: 07-11-2019 09:16
From: Unknown User
Subject: POE Controller Failure After Attempted Upgrade
Glad that it worked. Thanks for the confirmation.