Using Linux Mint 20.2 Cinnamon, Dell Inspiron 531.

When I put a USB card reader into a USB slot, nothing appears either on the desktop or in the file manager Nemo.

But when I use the command lsusb, it gives this result:

Bus 001 Device 010: ID 0000:0000 ENE UB6225

I get exactly the same results regardless of the SDHC card being in the reader or not.

Is there any way to activate it?

Thanks.

Update: I've found the verbose mode lsusb -v and the result is:

(It says "Couldn't open device, some information will be missing" for every device).

Bus 001 Device 011: ID 0000:0000 ENE UB6225
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0000
idProduct 0x0000
bcdDevice 0.00
iManufacturer 1
iProduct 2
iSerial 4
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0020
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0

The dmesg command produces pages and pages of output, mentions UB6225 seven or eight times perhaps because I have been pulling it in and out of the sockets,. The final part is:

[ 8593.738748] usb 1-10: new high-speed USB device number 12 using ehci-pci
[ 8593.895793] usb 1-10: New USB device found, idVendor=0cf2, idProduct=6225, bcdDevice= 1.00
[ 8593.895796] usb 1-10: New USB device strings: Mfr=1, Product=2, SerialNumber=4
[ 8593.895798] usb 1-10: Product: UB6225
[ 8593.895799] usb 1-10: Manufacturer: ENE
[ 8593.895800] usb 1-10: SerialNumber: 146030377350
[ 8593.896332] usb-storage 1-10:1.0: USB Mass Storage device detected
[ 8593.898798] scsi host6: usb-storage 1-10:1.0
[ 8594.931594] scsi 6:0:0:0: Direct-Access USB2.0 CardReader SD0 0100 PQ: 0 ANSI: 0
[ 8594.931966] scsi 6:0:0:0: Attached scsi generic sg2 type 0
[ 8594.963823] sd 6:0:0:0: [sdb] Attached SCSI removable disk
[ 8599.890575] [UFW BLOCK] IN=enp0s7 OUT= MAC=01:00:5e:00:00:01:54:13:10:e2:33:61:08:00 SRC=192.168.1.1 DST=224.0.0.1 LEN=32 TOS=0x00 PREC=0xC0 TTL=1 ID=786 PROTO=2

I'm not believing that device id of 0000:0000. So you have no module or firmware.
Look the specs of that device up on the web like you were buying it to find this sd card driver. Mine, for instance uses the Realtek RTS 5129 chip.

Then search for <your device> module & <your device> firmware, and post your results.

It could also be blown, which is quite on the cards.

Curiously, it does show in the Disks program, as Model USB2.0 CardReader SD0 (0000) Serial Number 146030377350.

It is a USB external device that plugs into an external USB socket.

I had appended some of the results from the dmesg command at the end of my post.

What is interesting is lsusb shows ID and vendor as zeros but dmesg shows the device being enumerated. I would assume the outputs were not at the same time so it is possible the device is not making a good connection when inserted all the time or something is intermittent.

If the device is recognized it should just work. Nothing will appear to happen on the desktop unless there is a card inserted with a filesystem. Typically new cards are already formatted as FAT or maybe exFAT.

Couldn't it literally be an off-brand or no-name device?

AFAIU, it's a USB hub, one that you plug into a USB port to make more ports, like an extension cord?
Those (the cheap ones) are notoriously ultra-low quality.

I eventually remembered that I also had a multi-card reader, which works perfectly. So I threw the duff one in the bin.

(They were both bought years ago from Poundland, both for £1 each as far as I recall. After they put every other pound-shop in Britain out of business and became a monopoly, the value-for-money has declined considerably and they no longer sell electronic gadgets.)