No serial port found

What is the problem?
My printer has now been running for over 12 months without fail & I always update Ocoprint when it says new update. Then today i was getting this error to the left side near the connection

No serial port found, are you sure your printer is physically connected and supported?

What did you already try to solve it?
I have tried several other USB cables & none sempt to do anything, I haven't changed any of the other settings as my printer has worked flawlessly for over 12 months as it is. So im doubtful changing settings now will do anything.

Have you tried running in safe mode?
Yes, it still says "no serial port found"

Systeminfo Bundle
octoprint-systeminfo-20221102210620.zip (145.9 KB)

Hope the system info bundle can help someone point me in the right direction of what to try next..

To be honest that doesn't sound good. Could be a hardwere problem on the printers mainboard.
But that doesn't mean you have to buy a new one.

Let's check if the printer is detected at all.

Log into your pi via ssh then disconnect your printer, connect it again, enter dmesg | tail -n 20 and post the output here.

That will show us if any device was detected.
If you want to test multiple cables and maybe want to wiggle the plugs a bit and want a continuous output enter dmesg -w.

The output should look something like this if a printer is detected:


pi@octopi:~ $ dmesg | tail -n 20
[   14.005793] Bluetooth: HCI UART driver ver 2.3
[   14.005800] Bluetooth: HCI UART protocol H4 registered
[   14.005833] Bluetooth: HCI UART protocol Three-wire (H5) registered
[   14.005929] Bluetooth: HCI UART protocol Broadcom registered
[   14.287152] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   14.287158] Bluetooth: BNEP filters: protocol multicast
[   14.287169] Bluetooth: BNEP socket layer initialized
[   14.342126] Bluetooth: RFCOMM TTY layer initialized
[   14.342141] Bluetooth: RFCOMM socket layer initialized
[   14.342164] Bluetooth: RFCOMM ver 1.11
[  112.504847] usb 1-1.4: new full-speed USB device number 5 using xhci_hcd
[  112.613099] usb 1-1.4: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.63
[  112.613106] usb 1-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  112.613110] usb 1-1.4: Product: USB2.0-Serial
[  112.652763] usbcore: registered new interface driver usbserial_generic
[  112.653040] usbserial: USB Serial support registered for generic
[  112.655699] usbcore: registered new interface driver ch341
[  112.655815] usbserial: USB Serial support registered for ch341-uart
[  112.655869] ch341 1-1.4:1.0: ch341-uart converter detected
[  112.658867] usb 1-1.4: ch341-uart converter now attached to ttyUSB0

If you need help with ssh connection, follow this guide

username: pi
password: raspberry

1 Like

Here's an update of what ive tried since my 1st post about this. I am now beginning to think its the main board on the printer thats on its way out...

Reson being, I have 2 identical printers both running on identical RP's. So after i re-installed Octoprint again on the (Green) none-working one with the fault & still had the same issues I decided to start swapping things from the (Orange) working one to the now none working one (Green)..

1st i swapped over the usb cables. Still didnt make any difference
2nd I swapped over the Pi's & still the same printer didnt work.

eventually, after what sempt a million reboots & swapping things about, The Green one picked up a Serial Port. So i set off a few test prints & all was good.

Then this morning after its been turned off all night Im now having the same problems with the green printer again... :sob: :sob: and its still has the PI's swapped over from yesterday. it has to be the printer..

I have no idea about logging in with SSH but i will look into it now..

many thanks for any help given..

:sob: :sob: Having problems with SSH all im getting is this.

C:\Users\baron>SSH ManCave@192.168.1.159
The authenticity of host '192.168.1.159 (192.168.1.159)' can't be established.
ECDSA key fingerprint is SHA256:z7D84O8s1I9n4uQ2GTMN1qApBIibVbP/tCjGTa/mRd8.
Are you sure you want to continue connecting (yes/no/[fingerprint])? y
Please type 'yes', 'no' or the fingerprint: yes
Warning: Permanently added '192.168.1.159' (ECDSA) to the list of known hosts.
ManCave@192.168.1.159's password:
Permission denied, please try again.
ManCave@192.168.1.159's password:
Permission denied, please try again.
ManCave@192.168.1.159's password:

I know for sure im putting the right password... but as i type the password its showing nothing on the screen as if the keyboard isnt working.? is this how it works..?

Yes, that's expected. You should type your password and then press enter. The credentials aren't the same as your OctoPrint credentials. The default is pi, with password raspberry. On your machine the username is definitely pi still (this is shown in the systeminfo bundle) so try logging in with that.

1 Like

Still having the same problems.
But ive worked out out to SSH it was the username i had wrong.

here is the logg. :man_shrugging: unfortunately it means nothing to me LOL..

------------------------------------------------------------------------------
OctoPrint version : 1.8.6
OctoPi version    : 0.18.0
------------------------------------------------------------------------------

pi@octopi:~ $ dmesg | tail -n 20
[    9.939884] 8021q: 802.1Q VLAN Support v1.8
[   10.099877] uart-pl011 3f201000.serial: no DMA platform data
[   10.224609] Adding 102396k swap on /var/swap.  Priority:-2 extents:22 across:149172k SSFS
[   10.484257] brcmfmac: brcmf_cfg80211_set_power_mgmt: power save enabled
[   10.874224] 8021q: adding VLAN 0 to HW filter on device eth0
[   15.997438] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   17.101798] Bluetooth: Core ver 2.22
[   17.101962] NET: Registered protocol family 31
[   17.101974] Bluetooth: HCI device and connection manager initialized
[   17.102751] Bluetooth: HCI socket layer initialized
[   17.102773] Bluetooth: L2CAP socket layer initialized
[   17.102813] Bluetooth: SCO socket layer initialized
[   17.116452] Bluetooth: HCI UART driver ver 2.3
[   17.116475] Bluetooth: HCI UART protocol H4 registered
[   17.116584] Bluetooth: HCI UART protocol Three-wire (H5) registered
[   17.116851] Bluetooth: HCI UART protocol Broadcom registered
[   17.376418] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   17.376434] Bluetooth: BNEP filters: protocol multicast
[   17.376461] Bluetooth: BNEP socket layer initialized
[   17.920319] ICMPv6: process `dhcpcd' is using deprecated sysctl (syscall) net.ipv6.neigh.wlan0.retrans_time - use net.ipv6.neigh.wlan0.retrans_time_ms instead
pi@octopi:~ $

BUMP Anyone with any ideas to this i would be appreciated thanks..

:sob: :sob: :sob: Now both printers are doing the same & can not connect with either..

whats happening to them.

is it the PI's or the printers?

I can still print if i go back to using the micro sd card. but this is going backwards not forwards...

please someone help.. :sos: :sos: :sos: :sos: :sos:

1.Make sure you have a data cable and not just a power cable

  1. Give the following commands in ssh and provide the results:
    sudo dmesg -C
    plug in printer by USB
    sudo dmesg

plug in to where by USB ? My PC or the PI.

they are data cables they have been working fine for over 12 months without problem.

The Pi. You are ssh'ing into the Pi, giving the command, plugging the printer into the Pi, then give the second command.

Finally got round do doing this without any more problems...

here is the result, it means nothing to me but hopefully it will do to you.

thanks for any advise given..

------------------------------------------------------------------------------
OctoPrint version : 1.8.6
OctoPi version    : 0.18.0
------------------------------------------------------------------------------

pi@octopi:~ $ sudo dmesg
[sudo] password for pi:
[    0.000000] Booting Linux on physical CPU 0x0
[    0.000000] Linux version 5.10.103-v7+ (dom@buildbot) (arm-linux-gnueabihf-gcc-8 (Ubuntu/Linaro 8.4.0-3ubuntu1) 8.4.0, GNU ld (GNU Binutils for Ubuntu) 2.34) #1529 SMP Tue Mar 8 12:21:37 GMT 2022
[    0.000000] CPU: ARMv7 Processor [410fd034] revision 4 (ARMv7), cr=10c5383d
[    0.000000] CPU: div instructions available: patching division code
[    0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[    0.000000] OF: fdt: Machine model: Raspberry Pi 3 Model B Plus Rev 1.3
[    0.000000] random: fast init done
[    0.000000] Memory policy: Data cache writealloc
[    0.000000] Reserved memory: created CMA memory pool at 0x34000000, size 64 MiB
[    0.000000] OF: reserved mem: initialized node linux,cma, compatible id shared-dma-pool
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000000000000-0x0000000037ffffff]
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000000000000-0x0000000037ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000037ffffff]
[    0.000000] On node 0 totalpages: 229376
[    0.000000]   DMA zone: 2016 pages used for memmap
[    0.000000]   DMA zone: 0 pages reserved
[    0.000000]   DMA zone: 229376 pages, LIFO batch:63
[    0.000000] percpu: Embedded 20 pages/cpu s50828 r8192 d22900 u81920
[    0.000000] pcpu-alloc: s50828 r8192 d22900 u81920 alloc=20*4096
[    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 227360
[    0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=0 snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2708_fb.fbswap=1 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  console=ttyS0,115200 console=tty1 root=PARTUUID=29d6532f-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
[    0.000000] Kernel parameter elevator= does not have any effect anymore.
               Please use sysfs to set IO scheduler for individual devices.
[    0.000000] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes, linear)
[    0.000000] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes, linear)
[    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
[    0.000000] Memory: 826024K/917504K available (10240K kernel code, 1312K rwdata, 2952K rodata, 1024K init, 862K bss, 25944K reserved, 65536K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1
[    0.000000] ftrace: allocating 32081 entries in 95 pages
[    0.000000] ftrace: allocated 94 pages with 5 groups
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000]  Rude variant of Tasks RCU enabled.
[    0.000000]  Tracing variant of Tasks RCU enabled.
[    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies.
[    0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16
[    0.000000] random: get_random_bytes called from start_kernel+0x3ac/0x580 with crng_init=1
[    0.000000] arch_timer: cp15 timer(s) running at 19.20MHz (phys).
[    0.000000] clocksource: arch_sys_counter: mask: 0xffffffffffffff max_cycles: 0x46d987e47, max_idle_ns: 440795202767 ns
[    0.000007] sched_clock: 56 bits at 19MHz, resolution 52ns, wraps every 4398046511078ns
[    0.000024] Switching to timer-based delay loop, resolution 52ns
[    0.000308] Console: colour dummy device 80x30
[    0.001170] printk: console [tty1] enabled
[    0.001238] Calibrating delay loop (skipped), value calculated using timer frequency.. 38.40 BogoMIPS (lpj=192000)
[    0.001296] pid_max: default: 32768 minimum: 301
[    0.001524] LSM: Security Framework initializing
[    0.001787] Mount-cache hash table entries: 2048 (order: 1, 8192 bytes, linear)
[    0.001836] Mountpoint-cache hash table entries: 2048 (order: 1, 8192 bytes, linear)
[    0.003308] cgroup: Disabling memory control group subsystem
[    0.003594] CPU: Testing write buffer coherency: ok
[    0.004110] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000
[    0.005366] Setting up static identity map for 0x100000 - 0x10003c
[    0.005575] rcu: Hierarchical SRCU implementation.
[    0.006515] smp: Bringing up secondary CPUs ...
[    0.007689] CPU1: thread -1, cpu 1, socket 0, mpidr 80000001
[    0.008965] CPU2: thread -1, cpu 2, socket 0, mpidr 80000002
[    0.010278] CPU3: thread -1, cpu 3, socket 0, mpidr 80000003
[    0.010435] smp: Brought up 1 node, 4 CPUs
[    0.010490] SMP: Total of 4 processors activated (153.60 BogoMIPS).
[    0.010521] CPU: All CPU(s) started in HYP mode.
[    0.010548] CPU: Virtualization extensions available.
[    0.011554] devtmpfs: initialized
[    0.029224] VFP support v0.3: implementor 41 architecture 3 part 40 variant 3 rev 4
[    0.029522] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
[    0.029584] futex hash table entries: 1024 (order: 4, 65536 bytes, linear)
[    0.032623] pinctrl core: initialized pinctrl subsystem
[    0.033835] NET: Registered protocol family 16
[    0.038098] DMA: preallocated 1024 KiB pool for atomic coherent allocations
[    0.043834] audit: initializing netlink subsys (disabled)
[    0.044147] audit: type=2000 audit(0.040:1): state=initialized audit_enabled=0 res=1
[    0.044741] thermal_sys: Registered thermal governor 'step_wise'
[    0.045736] hw-breakpoint: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
[    0.045799] hw-breakpoint: maximum watchpoint size is 8 bytes.
[    0.046120] Serial: AMBA PL011 UART driver
[    0.064397] bcm2835-mbox 3f00b880.mailbox: mailbox enabled
[    0.080152] raspberrypi-firmware soc:firmware: Attached to firmware from 2021-12-01T15:08:00, variant start_x
[    0.090163] raspberrypi-firmware soc:firmware: Firmware hash is 71bd3109023a0c8575585ba87cbb374d2eeb038f
[    0.134435] Kprobes globally optimized
[    0.139474] bcm2835-dma 3f007000.dma: DMA legacy API manager, dmachans=0x1
[    0.141835] SCSI subsystem initialized
[    0.142119] usbcore: registered new interface driver usbfs
[    0.142205] usbcore: registered new interface driver hub
[    0.142297] usbcore: registered new device driver usb
[    0.144305] clocksource: Switched to clocksource arch_sys_counter
[    1.861863] VFS: Disk quotas dquot_6.6.0
[    1.862007] VFS: Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
[    1.862232] FS-Cache: Loaded
[    1.862489] CacheFiles: Loaded
[    1.872473] NET: Registered protocol family 2
[    1.872770] IP idents hash table entries: 16384 (order: 5, 131072 bytes, linear)
[    1.874736] tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 6144 bytes, linear)
[    1.874831] TCP established hash table entries: 8192 (order: 3, 32768 bytes, linear)
[    1.874976] TCP bind hash table entries: 8192 (order: 4, 65536 bytes, linear)
[    1.875189] TCP: Hash tables configured (established 8192 bind 8192)
[    1.875394] UDP hash table entries: 512 (order: 2, 16384 bytes, linear)
[    1.875473] UDP-Lite hash table entries: 512 (order: 2, 16384 bytes, linear)
[    1.875791] NET: Registered protocol family 1
[    1.876597] RPC: Registered named UNIX socket transport module.
[    1.876631] RPC: Registered udp transport module.
[    1.876660] RPC: Registered tcp transport module.
[    1.876689] RPC: Registered tcp NFSv4.1 backchannel transport module.
[    1.878403] hw perfevents: enabled with armv7_cortex_a7 PMU driver, 7 counters available
[    1.882147] Initialise system trusted keyrings
[    1.882435] workingset: timestamp_bits=14 max_order=18 bucket_order=4
[    1.892001] zbud: loaded
[    1.894101] FS-Cache: Netfs 'nfs' registered for caching
[    1.895081] NFS: Registering the id_resolver key type
[    1.895165] Key type id_resolver registered
[    1.895195] Key type id_legacy registered
[    1.895363] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    1.895399] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[    1.896624] Key type asymmetric registered
[    1.896657] Asymmetric key parser 'x509' registered
[    1.896730] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 249)
[    1.896770] io scheduler mq-deadline registered
[    1.896800] io scheduler kyber registered
[    1.900299] bcm2708_fb soc:fb: FB found 1 display(s)
[    1.912556] Console: switching to colour frame buffer device 82x26
[    1.919859] bcm2708_fb soc:fb: Registered framebuffer for display 0, size 656x416
[    1.930450] bcm2835-rng 3f104000.rng: hwrng registered
[    1.933416] vc-mem: phys_addr:0x00000000 mem_base=0x3ec00000 mem_size:0x40000000(1024 MiB)
[    1.939359] gpiomem-bcm2835 3f200000.gpiomem: Initialised: Registers at 0x3f200000
[    1.956838] brd: module loaded
[    1.971580] loop: module loaded
[    1.976083] Loading iSCSI transport class v2.0-870.
[    1.980651] usbcore: registered new interface driver lan78xx
[    1.983386] usbcore: registered new interface driver smsc95xx
[    1.986014] dwc_otg: version 3.00a 10-AUG-2012 (platform bus)
[    2.716802] Core Release: 2.80a
[    2.719335] Setting default values for core params
[    2.721862] Finished setting default values for core params
[    2.924733] Using Buffer DMA mode
[    2.927171] Periodic Transfer Interrupt Enhancement - disabled
[    2.929725] Multiprocessor Interrupt Enhancement - disabled
[    2.932289] OTG VER PARAM: 0, OTG VER FLAG: 0
[    2.934843] Dedicated Tx FIFOs mode

[    2.937845] WARN::dwc_otg_hcd_init:1074: FIQ DMA bounce buffers: virt = b4114000 dma = 0xf4114000 len=9024
[    2.944970] FIQ FSM acceleration enabled for :
               Non-periodic Split Transactions
               Periodic Split Transactions
               High-Speed Isochronous Endpoints
               Interrupt/Control Split Transaction hack enabled
[    2.955949] dwc_otg: Microframe scheduler enabled

[    2.956031] WARN::hcd_init_fiq:457: FIQ on core 1

[    2.960357] WARN::hcd_init_fiq:458: FIQ ASM at 807cb8b8 length 36

[    2.964802] WARN::hcd_init_fiq:497: MPHI regs_base at b8810000
[    2.969268] dwc_otg 3f980000.usb: DWC OTG Controller
[    2.971584] dwc_otg 3f980000.usb: new USB bus registered, assigned bus number 1
[    2.973960] dwc_otg 3f980000.usb: irq 89, io mem 0x00000000
[    2.976306] Init: Port Power? op_state=1
[    2.978542] Init: Power Port (0)
[    2.981069] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.10
[    2.985690] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    2.988156] usb usb1: Product: DWC OTG Controller
[    2.990516] usb usb1: Manufacturer: Linux 5.10.103-v7+ dwc_otg_hcd
[    2.992916] usb usb1: SerialNumber: 3f980000.usb
[    2.996087] hub 1-0:1.0: USB hub found
[    2.998524] hub 1-0:1.0: 1 port detected
[    3.002360] dwc_otg: FIQ enabled
[    3.002373] dwc_otg: NAK holdoff enabled
[    3.002384] dwc_otg: FIQ split-transaction FSM enabled
[    3.002403] Module dwc_common_port init
[    3.002695] usbcore: registered new interface driver usb-storage
[    3.005387] mousedev: PS/2 mouse device common for all mice
[    3.009016] bcm2835-wdt bcm2835-wdt: Broadcom BCM2835 watchdog timer
[    3.014208] sdhci: Secure Digital Host Controller Interface driver
[    3.016799] sdhci: Copyright(c) Pierre Ossman
[    3.020042] mmc-bcm2835 3f300000.mmcnr: could not get clk, deferring probe
[    3.023291] sdhost-bcm2835 3f202000.mmc: could not get clk, deferring probe
[    3.026121] sdhci-pltfm: SDHCI platform and OF driver helper
[    3.030585] ledtrig-cpu: registered to indicate activity on CPUs
[    3.033603] hid: raw HID events driver (C) Jiri Kosina
[    3.036426] usbcore: registered new interface driver usbhid
[    3.039031] usbhid: USB HID core driver
[    3.046847] Initializing XFRM netlink socket
[    3.049463] NET: Registered protocol family 17
[    3.052091] Key type dns_resolver registered
[    3.055152] Registering SWP/SWPB emulation handler
[    3.057663] registered taskstats version 1
[    3.060003] Loading compiled-in X.509 certificates
[    3.063200] Key type ._fscrypt registered
[    3.065565] Key type .fscrypt registered
[    3.067900] Key type fscrypt-provisioning registered
[    3.081784] uart-pl011 3f201000.serial: cts_event_workaround enabled
[    3.084260] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 114, base_baud = 0) is a PL011 rev2
[    3.091388] bcm2835-power bcm2835-power: Broadcom BCM2835 power domains driver
[    3.095628] mmc-bcm2835 3f300000.mmcnr: mmc_debug:0 mmc_debug2:0
[    3.098105] mmc-bcm2835 3f300000.mmcnr: DMA channel allocated
[    3.125829] Indeed it is in host mode hprt0 = 00021501
[    3.188388] sdhost: log_buf @ (ptrval) (f4113000)
[    3.226469] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
[    3.230505] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    3.234431] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
[    3.239586] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
[    3.242865] mmc0: sdhost-bcm2835 loaded - DMA enabled (>1)
[    3.247962] of_cfs_init
[    3.250315] of_cfs_init: OK
[    3.253572] Waiting for root device PARTUUID=29d6532f-02...
[    3.333281] mmc1: new high speed SDIO card at address 0001
[    3.335466] usb 1-1: new high-speed USB device number 2 using dwc_otg
[    3.337692] mmc0: host does not support reading read-only switch, assuming write-enable
[    3.342202] Indeed it is in host mode hprt0 = 00001101
[    3.411639] mmc0: new high speed SDHC card at address aaaa
[    3.414865] mmcblk0: mmc0:aaaa SC32G 29.7 GiB
[    3.422820]  mmcblk0: p1 p2
[    3.449665] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[    3.454047] VFS: Mounted root (ext4 filesystem) readonly on device 179:2.
[    3.466356] devtmpfs: mounted
[    3.476168] Freeing unused kernel memory: 1024K
[    3.504825] Run /sbin/init as init process
[    3.507148]   with arguments:
[    3.507160]     /sbin/init
[    3.507170]   with environment:
[    3.507182]     HOME=/
[    3.507192]     TERM=linux
[    3.584744] usb 1-1: New USB device found, idVendor=0424, idProduct=2514, bcdDevice= b.b3
[    3.589829] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    3.593395] hub 1-1:1.0: USB hub found
[    3.596279] hub 1-1:1.0: 4 ports detected
[    3.914380] usb 1-1.1: new high-speed USB device number 3 using dwc_otg
[    4.044730] usb 1-1.1: New USB device found, idVendor=0424, idProduct=2514, bcdDevice= b.b3
[    4.050309] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    4.054034] hub 1-1.1:1.0: USB hub found
[    4.056963] hub 1-1.1:1.0: 3 ports detected
[    4.100537] systemd[1]: System time before build time, advancing clock.
[    4.154364] usb 1-1.2: new full-speed USB device number 4 using dwc_otg
[    4.244809] NET: Registered protocol family 10
[    4.249085] Segment Routing with IPv6
[    4.340338] systemd[1]: systemd 241 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN -PCRE2 default-hierarchy=hybrid)
[    4.350027] systemd[1]: Detected architecture arm.
[    4.428542] systemd[1]: Set hostname to <octopi>.
[    5.004381] usb 1-1.3: new high-speed USB device number 5 using dwc_otg
[    5.327262] random: systemd: uninitialized urandom read (16 bytes read)
[    5.346620] random: systemd: uninitialized urandom read (16 bytes read)
[    5.350154] systemd[1]: Set up automount Arbitrary Executable File Formats File System Automount Point.
[    5.359311] random: systemd: uninitialized urandom read (16 bytes read)
[    5.362829] systemd[1]: Listening on fsck to fsckd communication Socket.
[    5.369619] systemd[1]: Started Forward Password Requests to Wall Directory Watch.
[    5.380034] systemd[1]: Listening on Journal Audit Socket.
[    5.387342] systemd[1]: Listening on udev Kernel Socket.
[    5.396908] systemd[1]: Created slice system-systemd\x2dfsck.slice.
[    5.404110] systemd[1]: Listening on Journal Socket (/dev/log).
[    5.503706] usb 1-1.3: New USB device found, idVendor=0c45, idProduct=636b, bcdDevice= 1.00
[    5.509387] usb 1-1.3: New USB device strings: Mfr=2, Product=1, SerialNumber=3
[    5.509405] usb 1-1.3: Product: USB 2.0 Camera
[    5.514877] usb 1-1.3: Manufacturer: Sonix Technology Co., Ltd.
[    5.517706] usb 1-1.3: SerialNumber: SN0001
[    5.794565] usb 1-1.1.1: new high-speed USB device number 6 using dwc_otg
[    5.924958] usb 1-1.1.1: New USB device found, idVendor=0424, idProduct=7800, bcdDevice= 3.00
[    5.924984] usb 1-1.1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    6.190609] lan78xx 1-1.1.1:1.0 (unnamed net_device) (uninitialized): No External EEPROM. Setting MAC Speed
[    6.214649] lan78xx 1-1.1.1:1.0 (unnamed net_device) (uninitialized): int urb period 64
[    6.243607] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
[    6.382437] systemd-journald[111]: Received request to flush runtime journal from PID 1
[    6.867095] mc: Linux media interface: v0.10
[    6.907796] videodev: Linux video capture interface: v2.00
[    6.993363] usb 1-1.3: 3:1: cannot get freq at ep 0x84
[    7.000186] usbcore: registered new interface driver snd-usb-audio
[    7.018867] uvcvideo: Found UVC 1.00 device USB 2.0 Camera (0c45:636b)
[    7.036585] input: USB 2.0 Camera: USB 2.0 Camera as /devices/platform/soc/3f980000.usb/usb1/1-1/1-1.3/1-1.3:1.0/input/input0
[    7.037176] usbcore: registered new interface driver uvcvideo
[    7.037192] USB Video Class driver (1.1.1)
[    7.229219] vc_sm_cma: module is from the staging directory, the quality is unknown, you have been warned.
[    7.229839] vc_sm_cma: module is from the staging directory, the quality is unknown, you have been warned.
[    7.231868] bcm2835_vc_sm_cma_probe: Videocore shared memory driver
[    7.231897] [vc_sm_connected_init]: start
[    7.234870] vc_sm_cma: module is from the staging directory, the quality is unknown, you have been warned.
[    7.236005] vc_sm_cma: module is from the staging directory, the quality is unknown, you have been warned.
[    7.239126] [vc_sm_connected_init]: installed successfully
[    7.243345] bcm2835_mmal_vchiq: module is from the staging directory, the quality is unknown, you have been warned.
[    7.245205] bcm2835_mmal_vchiq: module is from the staging directory, the quality is unknown, you have been warned.
[    7.250956] snd_bcm2835: module is from the staging directory, the quality is unknown, you have been warned.
[    7.263722] bcm2835_isp: module is from the staging directory, the quality is unknown, you have been warned.
[    7.279338] bcm2835_audio bcm2835_audio: card created with 8 channels
[    7.281251] bcm2835_codec: module is from the staging directory, the quality is unknown, you have been warned.
[    7.294594] bcm2835_v4l2: module is from the staging directory, the quality is unknown, you have been warned.
[    7.294964] bcm2835-codec bcm2835-codec: Device registered as /dev/video10
[    7.295024] bcm2835-codec bcm2835-codec: Loaded V4L2 decode
[    7.302861] bcm2835-isp bcm2835-isp: Device node output[0] registered as /dev/video13
[    7.303521] bcm2835-codec bcm2835-codec: Device registered as /dev/video11
[    7.303536] bcm2835-isp bcm2835-isp: Device node capture[0] registered as /dev/video14
[    7.303590] bcm2835-codec bcm2835-codec: Loaded V4L2 encode
[    7.304468] bcm2835-isp bcm2835-isp: Device node capture[1] registered as /dev/video15
[    7.307308] bcm2835-isp bcm2835-isp: Device node stats[2] registered as /dev/video16
[    7.307348] bcm2835-isp bcm2835-isp: Register output node 0 with media controller
[    7.307374] bcm2835-isp bcm2835-isp: Register capture node 1 with media controller
[    7.307396] bcm2835-isp bcm2835-isp: Register capture node 2 with media controller
[    7.307417] bcm2835-isp bcm2835-isp: Register capture node 3 with media controller
[    7.307668] bcm2835-isp bcm2835-isp: Loaded V4L2 bcm2835-isp
[    7.307974] bcm2835-codec bcm2835-codec: Device registered as /dev/video12
[    7.308015] bcm2835-codec bcm2835-codec: Loaded V4L2 isp
[    7.310782] bcm2835-codec bcm2835-codec: Device registered as /dev/video18
[    7.310835] bcm2835-codec bcm2835-codec: Loaded V4L2 image_fx
[    7.677679] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[    7.770969] cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
[    7.877149] brcmfmac: F1 signature read @0x18000000=0x15264345
[    7.998794] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[    8.008029] usbcore: registered new interface driver brcmfmac
[    8.272989] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[    8.273135] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[    8.284791] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/6 wl0: Mar 23 2020 02:19:54 version 7.45.206 (r725000 CY) FWID 01-88ee44ea
[    9.693506] random: crng init done
[    9.693528] random: 7 urandom warning(s) missed due to ratelimiting
[   10.670732] uart-pl011 3f201000.serial: no DMA platform data
[   10.705759] 8021q: 802.1Q VLAN Support v1.8
[   11.004437] Adding 102396k swap on /var/swap.  Priority:-2 extents:22 across:149172k SSFS
[   11.205327] brcmfmac: brcmf_cfg80211_set_power_mgmt: power save enabled
[   11.601313] 8021q: adding VLAN 0 to HW filter on device eth0
[   17.771282] Bluetooth: Core ver 2.22
[   17.771426] NET: Registered protocol family 31
[   17.771441] Bluetooth: HCI device and connection manager initialized
[   17.771474] Bluetooth: HCI socket layer initialized
[   17.771495] Bluetooth: L2CAP socket layer initialized
[   17.771530] Bluetooth: SCO socket layer initialized
[   17.785646] Bluetooth: HCI UART driver ver 2.3
[   17.785671] Bluetooth: HCI UART protocol H4 registered
[   17.785793] Bluetooth: HCI UART protocol Three-wire (H5) registered
[   17.786077] Bluetooth: HCI UART protocol Broadcom registered
[   18.037459] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   18.037473] Bluetooth: BNEP filters: protocol multicast
[   18.037491] Bluetooth: BNEP socket layer initialized
[   22.275327] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   23.677812] ICMPv6: process `dhcpcd' is using deprecated sysctl (syscall) net.ipv6.neigh.wlan0.retrans_time - use net.ipv6.neigh.wlan0.retrans_time_ms instead
pi@octopi:~ $

Paste the results of running the exact commands I gave.
sudo dmesg -C
plug printer in by USB
sudo dmesg

I have done but nothing at all happens..

unless im doing something wrong..

I run your 1st command then plug in my usb cable to printer & run 2nd command.
nothing happens.

------------------------------------------------------------------------------
OctoPrint version : 1.8.6
OctoPi version    : 0.18.0
------------------------------------------------------------------------------

pi@octopi:~ $ sudo dmesg -C
[sudo] password for pi:
pi@octopi:~ $ sudo dmesg
pi@octopi:~ $

Since you got no solution yet - there might be the possibility of a hardware "hack".

We probably can connect the pi directly to the serial port pins on your printers mainboard.
Could you tell me the exact model name of the printer?
I'll try to find some pictures of the mainboard online and to figure out where those pins are.

both my printers are identical i got them at the same time.

both are Eryone Thinker s with the V2 board as they have the micro sd slot. where im sure the V1 had the large sd slot on it..

this link may help. Firmware For Thinker Series - Eryone 3D

This means your USB cable is almost certainly not a data cable.

they have to be, Ive been using them without problems for over 12 months now. so hows that work if they are not data cables.?

If that is the case, then your USB connector (or the USB->UART chip) is defective on your printer board. I would first explore the cable. If nothing shows up in dmesg it means the Pi does not see a device it can connect to.