N1548 reformat and restore file system. now only U-boot

I have a problem with a dell n1548 switch service tag 749----

I have reformated and restored file system on the switch and now it will only boot to the U-Boot menu

i have the latest firmware N1500v6.6.0.24.A08

but cannot find any way to get it on to the  switch

i have tried tftp and ymodem but cannot get either to work.

any help you could give would be amazing 

 

here is what the switch shows booting.

C03. Poll PLL Lock
C04. Calibrate ZQ (ddr40_phy_calib_zq)
C05. DDR PHY VTT On (Virtual VTT setup) DISABLE all Virtual VTT
C06. DDR40_PHY_DDR3_MISC
C07. VDL Calibration
C07.1
C07.2
C07.4
C07.4.1
C07.4.4
VDL calibration result: 0x30000003 (cal_steps = 0)
C07.4.5
C07.4.6
C07.5
C08. DDR40_PHY_DDR3_MISC : Start DDR40_PHY_RDLY_ODT....
C09. Start ddr40_phy_autoidle_on (MEM_SYS_PARAM_PHY_AUTO_IDLE) ....
C10. Wait for Phy ReadyDone.
DDR phy calibration passed
Programming controller register
ddr_init2: MemC initialization complete
Validate Shmoo parameters stored in flash ..... OK
Press Ctrl-C to run Shmoo ..... skipped
Restoring Shmoo parameters from flash ..... done
Running simple memory test ..... OK
DeepSleep wakeup: ddr init bypassed 3
DDR Interface Ready
CPLD: addr=0x21, rev=10
Board: L2 48 Port Copper Switch, Unkonwn
DRAM: 1 GiB
NAND: Micron MT29F1G08ABADA, 128 KiB blocks, 2 KiB pages, 16B OOB, 8-bit
NAND: chipsize 128 MiB
In: serial
Out: serial
Err: serial
arm_clk=1000MHz, axi_clk=400MHz, apb_clk=100MHz, arm_periph_clk=500MHz
Unlocking L2 Cache ...Done
l2cc_invalidate - Done, i = 970, invway = 0
Net: Registering eth
Broadcom BCM IPROC Ethernet driver 0.1
Using GMAC0 (0x18022000)
et0: ethHw_chipAttach: Chip ID: 0xdb56; phyaddr: 0x1
ethHw_miiphy_write (addr&f):phyaddr (addr&1f00):bank
ethHw_miiphy_write phyaddr(0x1) bank(0x0) reg(0x0) data(0x2100)
bcmiproc_eth-0
========== relocate address: 0xdff7c000, offset 0xc1f7c000 ==========
boot in 3 s
Creating 1 MTD partitions on "nand0":
0x000000200000-0x000007000000 : "mtd=4"
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size: 131072 bytes (128 KiB)
UBI: logical eraseblock size: 126976 bytes
UBI: smallest flash I/O unit: 2048
UBI: VID header offset: 2048 (aligned 2048)
UBI: data offset: 4096
UBI: attached mtd1 to ubi0
UBI: MTD device name: "mtd=4"
UBI: MTD device size: 110 MiB
UBI: number of good PEBs: 880
UBI: number of bad PEBs: 0
UBI: max. allowed volumes: 128
UBI: wear-leveling threshold: 4096
UBI: number of internal volumes: 1
UBI: number of user volumes: 1
UBI: available PEBs: 8
UBI: total number of reserved PEBs: 872
UBI: number of PEBs reserved for bad PEB handling: 8
UBI: max/mean erase counter: 6/2
UBIFS: mounted UBI device 0, volume 0, name "fs"
UBIFS: mounted read-only
UBIFS: file system size: 107802624 bytes (105276 KiB, 102 MiB, 849 LEBs)
UBIFS: journal size: 5459968 bytes (5332 KiB, 5 MiB, 43 LEBs)
UBIFS: media format: w4/r0 (latest is w4/r0)
UBIFS: default compressor: LZO
UBIFS: reserved for root: 5182151 bytes (5060 KiB)
/image2 not found!
ubifsload - load file from an UBIFS filesystem

Usage:
ubifsload [bytes]
- load file 'filename' to address 'addr'
Wrong Image Format for bootm command
ERROR: can't get kernel image!
Saving Environment to NAND...
Erasing Nand...
Erasing at 0x160000 -- 100% complete.
Writing to Nand... done
/image1 not found!
ubifsload - load file from an UBIFS filesystem

Usage:
ubifsload [bytes]
- load file 'filename' to address 'addr'
Wrong Image Format for bootm command
ERROR: can't get kernel image!
u-boot> ubifsls
63 Fri Jul 10 03:59:55 2020 serboot_config.md5sum
114 Fri Jul 10 03:59:55 2020 netboot_config
37 Fri Jul 10 03:59:55 2020 serboot_config
63 Fri Jul 10 03:59:55 2020 netboot_config.md5sum
u-boot>