How to fix SD card that keeps disconnecting and reconnecting?
Sophia Terry 
I have an old iMac 2013 with Intel® Core™ i5-4570S CPU @ 2.90GHz × 4 running UBUNTU 21.04
Doesn't matter if I connect the SD cards (all of them) in the built in SD card reader or if I use an USB card reader, the problem is very similar. The card connect and disconnect randomly. Normally, on the built-in reader, it can stay on may be a minute or two every time. On the USB card reader it may stay on a few seconds at the time.
guy@guy-iMac:~$ lspci
00:00.0 Host bridge: Intel Corporation 4th Gen Core Processor DRAM Controller (rev 06)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller (rev 06)
00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d5)
00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5)
00:1c.4 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5 (rev d5)
00:1f.0 ISA bridge: Intel Corporation Z87 Express LPC Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode] (rev 05)
00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GT 750M Mac Edition] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GK107 HDMI Audio Controller (rev a1)
03:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4360 802.11ac Wireless Network Adapter (rev 03)
04:00.0 Ethernet controller: Broadcom Inc. and subsidiaries NetXtreme BCM57766 Gigabit Ethernet PCIe (rev 01)
04:00.1 SD Host controller: Broadcom Inc. and subsidiaries BCM57765/57785 SDXC/MMC Card Reader (rev 01)
05:00.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
06:00.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
06:03.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
06:04.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
06:05.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
06:06.0 PCI bridge: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
07:00.0 System peripheral: Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012] (rev 03)
guy@guy-iMac:~$ The USB:
guy@guy-iMac:~$ lsusb
Bus 002 Device 009: ID 0bda:0306 Realtek Semiconductor Corp. USB3.0 Card Reader
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 007: ID 05ac:828d Apple, Inc. Bluetooth USB Host Controller
Bus 001 Device 004: ID 0a5c:4500 Broadcom Corp. BCM2046B1 USB 2.0 Hub (part of BCM2046 Bluetooth)
Bus 001 Device 003: ID 05ac:8511 Apple, Inc. FaceTime HD Camera (Built-in)
Bus 001 Device 002: ID 046d:c52b Logitech, Inc. Unifying Receiver
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
guy@guy-iMac:~$ How can I investigate this problem?
Please note that the journalCTL rport this
(Bare in mind that I'm fairly new at Linux so I do not understand everything here) but the lines in RED starting at nov 24 20:38:55 sounds bad...
nov 24 20:38:27 guy-iMac kernel: scsi 4:0:0:1: Attached scsi generic sg2 type 0
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:1: [sdc] 30294016 512-byte logical blocks: (15.5 GB/14.4 GiB)
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:1: [sdc] Write Protect is off
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:1: [sdc] Mode Sense: 2f 00 00 00
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:1: [sdc] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:0: [sdb] Attached SCSI removable disk
nov 24 20:38:28 guy-iMac kernel: sdc: sdc1
nov 24 20:38:28 guy-iMac kernel: sd 4:0:0:1: [sdc] Attached SCSI removable disk
nov 24 20:38:28 guy-iMac kernel: FAT-fs (sdc1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
nov 24 20:38:28 guy-iMac udisksd[783]: Mounted /dev/sdc1 at /media/guy/Prusa on behalf of uid 1000
nov 24 20:38:28 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Activating via systemd: service name='org.freedesktop.Tracker1' unit='tracker-store.service' requested by >
nov 24 20:38:28 guy-iMac systemd[938]: Starting Tracker metadata database store and lookup manager...
nov 24 20:38:28 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Activating service name='org.gnome.Shell.HotplugSniffer' requested by ':1.42' (uid=1000 pid=1272 comm="/us>
nov 24 20:38:28 guy-iMac systemd[938]: Started Tracker metadata database store and lookup manager.
nov 24 20:38:28 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Successfully activated service 'org.freedesktop.Tracker1'
nov 24 20:38:28 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Successfully activated service 'org.gnome.Shell.HotplugSniffer'
nov 24 20:38:35 guy-iMac systemd[1]: fprintd.service: Succeeded.
nov 24 20:38:37 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Activating service name='org.gnome.Nautilus' requested by ':1.379' (uid=1000 pid=22484 comm="gjs /usr/shar>
nov 24 20:38:38 guy-iMac dbus-daemon[971]: [session uid=1000 pid=971] Successfully activated service 'org.gnome.Nautilus'
nov 24 20:38:38 guy-iMac dbus-daemon[751]: [system] Activating via systemd: service name='org.freedesktop.hostname1' unit='dbus-org.freedesktop.hostname1.service' requested by >
nov 24 20:38:38 guy-iMac systemd[1]: Starting Hostname Service...
nov 24 20:38:38 guy-iMac dbus-daemon[751]: [system] Successfully activated service 'org.freedesktop.hostname1'
nov 24 20:38:38 guy-iMac systemd[1]: Started Hostname Service.
nov 24 20:38:38 guy-iMac nautilus[22637]: Called "net usershare info" but it failed: L’exécution du processus fils « net » a échoué (No such file or directory)
nov 24 20:38:48 guy-iMac NetworkManager[755]: <info> [1637804328.0287] manager: NetworkManager state is now CONNECTED_LOCAL
nov 24 20:38:48 guy-iMac NetworkManager[755]: <info> [1637804328.0288] manager: NetworkManager state is now CONNECTED_SITE
nov 24 20:38:48 guy-iMac NetworkManager[755]: <info> [1637804328.0290] policy: set 'Connexion filaire 1' (enp4s0f0) as default for IPv4 routing and DNS
nov 24 20:38:55 guy-iMac kernel: usb 2-1: USB disconnect, device number 42
nov 24 20:38:55 guy-iMac kernel: blk_update_request: I/O error, dev sdc, sector 2049 op 0x1:(WRITE) flags 0x0 phys_seg 1 prio class 0
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 1, lost async page write
nov 24 20:38:55 guy-iMac kernel: blk_update_request: I/O error, dev sdc, sector 31654 op 0x1:(WRITE) flags 0x0 phys_seg 2 prio class 0
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 29606, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 29607, lost async page write
nov 24 20:38:55 guy-iMac kernel: blk_update_request: I/O error, dev sdc, sector 81840 op 0x1:(WRITE) flags 0x0 phys_seg 1 prio class 0
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79792, lost async page write
nov 24 20:38:55 guy-iMac kernel: blk_update_request: I/O error, dev sdc, sector 81856 op 0x1:(WRITE) flags 0x0 phys_seg 6 prio class 0
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79808, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79809, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79810, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79811, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79812, lost async page write
nov 24 20:38:55 guy-iMac kernel: Buffer I/O error on dev sdc1, logical block 79813, lost async page write
nov 24 20:38:55 guy-iMac kernel: blk_update_request: I/O error, dev sdc, sector 81874 op 0x1:(WRITE) flags 0x0 phys_seg 3 prio class 0
nov 24 20:38:55 guy-iMac udisksd[783]: Cleaning up mount point /media/guy/Prusa (device 8:33 no longer exists)
nov 24 20:38:55 guy-iMac systemd[938]: media-guy-Prusa.mount: Succeeded.
nov 24 20:38:55 guy-iMac systemd[1]: media-guy-Prusa.mount: Succeeded.
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