Hmm, try interrupting the boot at the loader. Will it reboot from there:
+---- Welcome to Netgate pfSense Plus ----+ __________________________
| | / ___\
| 1. Boot Multi user [Enter] | | /`
| 2. Boot Single user | | / :-|
| 3. Escape to loader prompt | | _________ ___/ /_ |
| 4. Reboot | | /` ____ / /__ ___/ |
| 5. Cons: Dual (Serial primary) | | / / / / / / |
| | | / /___/ / / / |
| Options: | | / ______/ / / _ |
| 6. Kernel: default/kernel (1 of 2) | |/ / / / _| |_ |
| 7. Boot Options | / /___/ |_ _| |
| 8. Boot Environments | / |_| |
| | /_________________________/
+-----------------------------------------+ \
Exiting menu!
Type '?' for a list of commands, 'help' for more detailed help.
OK reboot
Will it reset from the uboot prompt?:
U-Boot 2018.03-devel-18.12.3-gc9aa92c-dirty (Oct 07 2021 - 18:20:55 -0300)
Model: Netgate 1100
CPU 1200 [MHz]
L2 800 [MHz]
TClock 200 [MHz]
DDR 750 [MHz]
DRAM: 1 GiB
Comphy chip #0:
Comphy-0: USB3 5 Gbps
Comphy-1: PEX0 2.5 Gbps
Comphy-2: SATA0 6 Gbps
SATA link 0 timeout.
AHCI 0001.0300 32 slots 1 ports 6 Gbps 0x1 impl SATA mode
flags: ncq led only pmp fbss pio slum part sxs
PCIE-0: Link down
MMC: sdhci@d0000: 0, sdhci@d8000: 1
Loading Environment from SPI Flash... SF: Detected mx25u3235f with page size 256 Bytes, erase size 64 KiB, total 4 MiB
OK
Model: Netgate 1100
Net: eth0: neta@30000 [PRIME]
Read - switch port: 0x1, page: 0x0, reg: 0x0, val: 0xFFFF
Read - switch port: 0x2, page: 0x0, reg: 0x0, val: 0xFFFF
Switch Ports Disabled
Hit any key to stop autoboot: 0
Marvell>> reset
If it won't do either of those it's almost certainly a hardware fault.