Cisco C9200 Stack Failed, BOOTING GOLDEN, mode SMON1@M3.0

[DagKlose]

Dear Cisco Community, 

I've a big problem:

A Software Update on a Cisco 9200 Stack failed, because the power supply accindentally got cut off while the update was happening. Now one Cisco Switch is working fine, the other one is stuck in the following mode:

Initializing Hardware...

Image Error: could not find valid header...

!!PRIMARY ROMMON CORRUPTED, BOOTING GOLDEN!!

Image Error: could not find valid header...
BOOT FAILED!!!!

Press ENTER to power cycle or ESC within 0 secs to spawn SMON...

Initializing Hardware...

Image Error: could not find valid header...

!!PRIMARY ROMMON CORRUPTED, BOOTING GOLDEN!!

Image Error: could not find valid header...
BOOT FAILED!!!!

Press ENTER to power cycle or ESC within 9 secs to spawn SMON...

[SMON v80 rel_17_9_1r_fc4 20220323-083301]

* Use 'help' to list commands; 'help <command>' shows command details
* '<...>' indicates an argument; '[...]' indicates optional arguments
* Use single-space delimitors between all command arguments
* Use a '0x' prefix to indicate hex digits for numerical arguments
* Disk numbers are (0,1=SPI 3=SRAM)

SMON1@M3.0> help

* Use 'help' to list commands; 'help <command>' shows command details
* '<...>' indicates an argument; '[...]' indicates optional arguments
* Use single-space delimitors between all command arguments
* Use a '0x' prefix to indicate hex digits for numerical arguments
* Disk numbers are (0,1=SPI 3=SRAM)

boot -- Boot Cortex-As to an optional image file or address
bootd -- Boot Cortex-A, enable debugs and spawn SMON on M3.1 and the other UART
envvar -- Display SMON Environment Variables
help -- List command information
history -- Show command history
initdram -- Initialize DRAM manually
reset -- Reset entire CrayCore complex
uptime -- Display SMON uptime
SMON1@M3.0>
SMON1@M3.0>

I've never seen this kind of problem before and I dont know how to solve it. 

Even if you stack the switches or try to boot it in single switch mode (not in Stack mode) this switch just ends up in this unknown SMON1 mode. Hm. 

Is there someone who knows how to fix that?

[Kasun Bandara]

seems like boot loader is corrupted. better get support from TAC. go to support.cisco.com and open a support case

[balaji.bandi]

how many devices in the stack ? one working leave it as it is

and the one on ROMMON, remove from STACK and do to image recovery

follow below thread :

https://community.cisco.com/t5/switches-small-business/cannot-load-ios-image-in-rommon-mode-cisco-catalyst-9200/td-p/3944645

[Leo Laohoo]

RMA the switch.  

The microcode is corrupt.