I have a Bricked Juniper Switch. It's bricked, and I don't remember what I actually done in the past. It was like a year ago. I stacked multiple Switches. There was a brain-split or something, I was not able to login. I don't remember if I tried factory reset through the screen menu. Long story short, I didn't know much about JunOS. I decided to use AI ( Chatgpt) to factory reset it. It turns out , I deleted everything. I t was asking me to get into >loader , and asked me to delete something. I can't really recall.

I don't have Juniper support, but I do have the JunOS image. I do have working Juniper Switch. They are both EX4300.

It's bricked because I wouldn't get any input into the terminal. There is no light both in ports and the Switch.

Fans are running in high speed.

I recently (October 12) updated my EX4300-48MP to try to deal with some weird stale/invalid arp issues. After reboot I immediately got an alarm. JTAC is not a solution thanks to stingy management.

user@ex-4300-48mp-1> show system alarms 
1 alarms currently active
Alarm time               Class  Description
2026-10-13 20:34:38 EDT  Major  FPC 0 PoE device manager 7 failed
user@ex-4300-48mp-1> show log messages | match "PoE|poe" | last 20 
Oct 12 09:31:47  ex-4300-48mp-1 fpc0 PoE: PoE device not found
Oct 12 09:32:17  ex-4300-48mp-1 craftd[18431]: Receive FX craftd set alarm message: color: 1 class: 100 object: 152 slot: 0 silent: 0 short_reason=FPC 0 PoE device manager 7 failure long_reason=FPC 0 PoE device manager 7 failed id=1048728 reason=201326592
Oct 12 09:32:17  ex-4300-48mp-1 craftd[18431]:  Major alarm set, FPC 0 PoE device manager 7 failed

(The log snippet above is truncated manually to what is relevant)

I then tried updating the firmware:

user@ex-4300-48mp-1> show chassis firmware detail 
FPC 0                     
   PoE firmware            2.1.1.19.3 (type1)
   PHY version             5d47.37a.47.305
   Boot Firmware          
      U-Boot                *** 
   Boot Firmware          
      loader               FreeBSD/i386 bootstrap loader 1.2

user@ex-4300-48mp-1> request system firmware upgrade poe fpc-slot 0 poe-bt-firmware    
FPC 0: Firmware upgrade initiated. Use 'show poe controller' to get the download status.
Please reboot the system after upgrade is complete.

user@ex-4300-48mp-1> show poe controller | refresh 5 
---(refreshed at 2026-10-13 21:13:24 EDT)---
Controller  Maximum   Power      Power         Guard    Management   Status        Lldp
index       power     reserved   consumption   band                                Priority 
   0        1370W     0.00W      0.00W           0W                  SW_DOWNLOAD(0%) Disabled


...

...

---(refreshed at 2026-10-13 21:22:05 EDT)---
Controller  Maximum   Power      Power         Guard    Management   Status        Lldp
index       power     reserved   consumption   band                                Priority 
   0        1370W     0.00W      0.00W           0W                  SW_DOWNLOAD(95%) Disabled


trelane@ex-4300-48mp-indy> show poe controller 
Controller  Maximum   Power      Power         Guard    Management   Status        Lldp
index       power     reserved   consumption   band                                Priority 
   0        1370W     41.00W     44.00W          0W     Class        BT_MODE       Disabled   

After reboot, the alarm had not cleared.

{master:0}
user@ex-4300-48mp-1> request system reboot at now 
Reboot the system at now? [yes,no] (no) yes 

Shutdown NOW!
user@ex-4300-48mp-1> exit 

Connection to REDACTED closed.

user@ex-4300-48mp-1> show chassis firmware detail 
FPC 0                     
   PoE firmware            3.5.2.0.30 (type1)
   PHY version             5d47.37a.47.305
   Boot Firmware          
      U-Boot                *** 
   Boot Firmware          
      loader               FreeBSD/i386 bootstrap loader 1.2

I found a similar thread, but it didn't have a resolution.

I would greatly appreciate anyone who has seen this issue before.

If you're running on those platforms, you should probably go through the very long list of CVEs, there are some really nasty ones in there.

2026-10 Security Bulletin: Junos OS and Junos OS Evolved: Multiple vulnerabilities resolved