Ubiquiti LAP-120 bricked

I got this device, because it´s officially supported by Openwrt. For installing the current release i used the procedure described here
After reboot the device is not responding. So I opened the case, looked for uart pins and got an serial cable connected.
Some lines are scrambled:

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с[    0.000000] Ьinѕx version 5.15.1Г4 Јbuilder@buildшosє) (mips-openwrt-ьinѕx-musl-gcc (O№enзrt GCC 12.3.0 r2Г49З-6637af95aa) 12.Г.0Ќ GNU ld (GNU Тinѕtils) 2.40.0) #0 Moю Oct 9 21:45:Г5 В023
[    0.000000] pђinєk: bootconsole [хarьy0] enabled
[    А.0А0000] CPU0 revisщon is: 0001974c ЈMIаS 74Kc)
[    0.А00А00] SoC: Atheros ARЙ342 rev 3 ЬiteAP ac (LAP-12А)
[    0.000000] Initrd noє found or empty ­ dщsabling initrф
[    0Ў00А000] Primary insєruуtion cache 64kB, VIаT, 4-way, linхsiњe 32 bytes.
[    0.0А00А0] Primary daєa уache 32kB, 4-wayЌ VЩPT, cache aliсseѓ, linesize 32 byєes
                                                                                     [    0.000000] Zonх rсnges:
[    А.0А0000]   Normaь   [mem 0x000000000А00А000-0x0000000003цffцff]
[    А.000000] Movaтle zone start for eсch node
[    0.000000] Early эemяry node ranges
[    А.000000]   node   0К [mem 0x00000000А00А0000-0x000000А00Гffffff]
[    0.00000А] Щnitmem setup юodх 0 [mem 0x000000А00А000000-0x0000000А03цfffff]
[    0.000000] Buщlt 1 zonelists, эobщlity grouping onЎ  Total pages: 1Ж24А
[    0.000000] Kхrnхl command line: уonѓole=ttyS0,115В00 rootfstype=squasшfsЌjffs2
[    0.А00А00] Dentry cache haѓh table entriхs: 8192 (order: 3, Г27Ж8 bytes, linear)
[    А.0А0000] Writing ErђCtl register=000А00А0                                     [    0.А00А00] Inode-cacшe шash table entrieѓ: Д096 (order: 2Ќ 1Ж384 bytes, lineaђ)
[    0.А00000] Readback ХrrУtl register=0000А000
[    0.000А00н mem auto-iniє: ѓtack:off, heap aьloу:off, heap free:яff
л    0.000000] Meэorљ: 55976K/65536K сvaщlable (6077K kerюel code, 591K rwфatс, 780K rodata, 1Б84Ы init, 217K bѓs, 9560K reserved, АK уma-reserved)
[    0.0000А0] SLUB: HWalign=32Ќ Oђder=0-3, MinOтjeуts=0, CPUs=1, NoфesН1
[    0.00000А] ЮR_IRQS: 51
[    А.0А0000] CPU clock: 53Е.000 MHz
[    0Ў00А000] clocksouђceК MIPS: mask: 0xfцffцfff max_cycles: Аxfцffffff, max_iфleпns: 7144898866 nѓ
[    0.000002] schхd_уlock: 32 bits at 267MHz, resolutiяn Гns, wraps every И02З976190ns
[    0.008431н Cсlibrating delсy ьoop... 266.64 BoчoMЩPS (lpj=13332Д8)
                                                                      л    0.095027] pid_mсx: default: 3276И mщnimum: 301
[    А.1А8988] Mountpoint­cache hash table enєries: 1024 (ordeђ: А, 4096 bytes, liюear)
[    0.126А03н clocksource: jiцfiхs: mask: 0xfffffцff max_cycles: 0јffцfffff, max_idle_юs: 1911260446275А00А ns
[    0.136Е61н futex hash tablх eюtries: 256 (oђdeђ: -1, 3072 bytesЌ lщnear)
[    0.144101] pinуtrь core: initializхd №inctrl subsysєem
                                                          [    0Ў152098] NET: вegщstered PF_NETLINЫ/PЦ_ROUTE protocяl цamily
[    0Ў15Й217] thermal_sysК Rхgistered therэal governor 'step_wщseЇ
[    0.17Д66З] clocksourceК Sїitched to clocksяurуe MIPS
[    0.18И41Ж] NET: Registereф PЦ_INET protocoь fсmily
[    А.202927] tcp_ьisєen_portaddr_hash haѓh table entriхs: 512 (order: 0, 4А96 bytes, linear)
л    0.211957] Table­peђturb hash tabьe хntries: 65536 (oђdeђ: 6, 262144 byteѓ, linear)
[    0.220247] TCа established шasш table entries: Б02Д (order: 0, 4096 bytes, linear)
[    0.22И43З] TCP bind haѓh єable entries: 10В4 Јorder: 0, 409Ж bљtes, linear)
л    0.235974] TCа: Шash tables confiчurхd (establisheф 1А24 bind 1024)
[    0.В42972] UDP hash єabьe entries: 25Ж (яrder: 0, 4096 byєesЌ linear)
[    0.250027] UDP-Liєe шash table entђieѓ: 256 (order: 0, 40Й6 bytes, lineсr)
                                                                              [    0.2Е79И9] NET: Regisєerхd PF_UNIX/PF_LOCСL №rotocol familљ
[    0.27В99Й] workingset: tiэesєamp_bits=14 mсx_яrder=14 bucket_oђdeђ=0
[    А.2И6922] squashfs: іerѓion 4.0 (2009/01Џ31) Phillip Lougшer
                                                                 л    0.293150] jffs2К vхrsion 2.2 (NAЮD) (SUMMARY) (LZMA) (RдIME) (CMODE_PвIOвITY) (c) 2001-20А6 вed Hat, Inc.
[    0.305550] Bloуk ьayer SCSI generiу (тsg) driver versiяn А.4 loaded (maъor 251)
л    0.318701] piюctђl-single 1804002у.pщnmux: 544 pins, ѓizх 68
[    0.326392] Sхriсl: 8250/16550 drщver, 16 ports, IвQ ѓharing enabled
[    0Ў336822] printk: уonѓole [ttyS0] dщsaтled
[    0Ў34Б480] 18020000.uaђt: ttyS0 at MMIO 0xБ80В0000 (irq = 9Ќ bсse_baud = 250000А) щs a 16550A
[    0.350760] printk: console [ttyS0] enabled
[    0.350760] printk: console [ttyS0] enabled
[    0.359676] printk: bootconsole [early0] disabled
[    0.359676] printk: bootconsole [early0] disabled
[    0.394111] spi-nor spi0.0: mx25l12805d (16384 Kbytes)
[    0.399516] 5 fixed-partitions partitions found on MTD device spi0.0
[    0.406050] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
[    0.412818] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
[    0.419959] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
[    0.426775] OF: Bad cell count for /ahb/spi@1f000000/flash@0/partitions
[    0.434068] Creating 5 MTD partitions on "spi0.0":
[    0.439017] 0x000000000000-0x000000040000 : "u-boot"
[    0.450736] 0x000000040000-0x000000050000 : "u-boot-env"
[    0.457564] 0x000000050000-0x000000fb0000 : "firmware"
[    0.466713] 2 uimage-fw partitions found on MTD device firmware
[    0.472753] Creating 2 MTD partitions on "firmware":
[    0.477857] 0x000000000000-0x000000240000 : "kernel"
[    0.484298] 0x000000240000-0x000000f60000 : "rootfs"
[    0.492882] mtd: setting mtd4 (rootfs) as root device
[    0.498216] 1 squashfs-split partitions found on MTD device rootfs
[    0.504511] 0x000000620000-0x000000f60000 : "rootfs_data"
[    0.511584] 0x000000fb0000-0x000000ff0000 : "cfg"
[    0.519906] 0x000000ff0000-0x000001000000 : "art"
[    1.015335] ag71xx 19000000.eth: connected to PHY at mdio.0:04 [uid=004dd072, driver=Qualcomm Atheros AR8035]
[    1.026319] eth0: Atheros AG71xx at 0xb9000000, irq 4, mode: rgmii-id
[    1.033585] i2c_dev: i2c /dev entries driver
[    1.040422] NET: Registered PF_INET6 protocol family
[    1.056039] Segment Routing with IPv6
[    1.059917] In-situ OAM (IOAM) with IPv6
[    1.064058] NET: Registered PF_PACKET protocol family
[    1.069366] bridge: filtering via arp/ip/ip6tables is no longer available by default. Update your scripts to load br_netfilter if you need this.
[    1.082958] 8021q: 802.1Q VLAN Support v1.8
[    1.089144] PCI host bridge to bus 0000:00
[    1.093332] pci_bus 0000:00: root bus resource [mem 0x10000000-0x13ffffff]
[    1.100390] pci_bus 0000:00: root bus resource [io  0x0000]
[    1.106064] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff]
[    1.114214] pci 0000:00:00.0: [0777:11ac] type 00 class 0x028000
[    1.120393] pci 0000:00:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit]
[    1.127357] pci 0000:00:00.0: reg 0x30: [mem 0x00000000-0x0000ffff pref]
[    1.134248] pci 0000:00:00.0: supports D1 D2
[    1.139806] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 00
[    1.146611] pci 0000:00:00.0: BAR 0: assigned [mem 0x10000000-0x101fffff 64bit]
[    1.154057] pci 0000:00:00.0: BAR 6: assigned [mem 0x10200000-0x1020ffff pref]
[    1.167356] unable to read id index table
[    1.172099] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000000: 0x6873 instead
[    1.181945] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000004: 0x5805 instead
[    1.191661] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000008: 0x7f74 instead
[    1.201311] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000010: 0x2d00 instead
[    1.210947] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000014: 0x0400 instead
[    1.220582] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000018: 0xc002 instead
[    1.230217] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0000001c: 0x0400 instead
[    1.239854] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000020: 0x6910 instead
[    1.249490] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000028: 0x1478 instead
[    1.259126] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00000030: 0x0c78 instead
[    1.268761] jffs2: Further such events for this erase block will not be printed
[    1.278548] jffs2: Empty flash at 0x00000038 ends at 0x00000040
[    1.323178] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010000: 0x6664 instead
[    1.332845] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010004: 0x6281 instead
[    1.342481] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010008: 0x34df instead
[    1.352116] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0001000c: 0x7b31 instead
[    1.361751] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010010: 0x7994 instead
[    1.371378] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010014: 0x51b1 instead
[    1.381006] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010018: 0x81f7 instead
[    1.390632] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0001001c: 0xcc5d instead
[    1.400259] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010020: 0x9496 instead
[    1.409893] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00010024: 0xef14 instead
[    1.419523] jffs2: Further such events for this erase block will not be printed
[    1.467727] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020000: 0x6f6c instead
[    1.477393] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020004: 0x3d50 instead
[    1.487030] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020008: 0x375e instead
[    1.496663] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0002000c: 0x1509 instead
[    1.506291] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020010: 0x974e instead
[    1.515925] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020014: 0x1dd9 instead
[    1.525556] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020018: 0x96fc instead
[    1.535190] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x0002001c: 0xfef1 instead
[    1.544817] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020020: 0xd014 instead
[    1.554434] jffs2: jffs2_scan_eraseblock(): Magic bitmask 0x1985 not found at 0x00020024: 0x77e5 instead

Is there any chance to get a readable bootmenu or to restore u-boot? ATM there should be a clearly hint on the site, as the instructions not working

Thanks in advance
Go

serial speed probably changes between boot loader and kernel.

Do you have suggestions? I tried IMHO all speeds down to 2400, but I dont want to play with 2 stop bits or 7bit. Combinations are endless...

With regards
Go