Hello, First of all, thanks a lot for your efforts to improve the community. I just found this thread looking for a solution to a problematic ticket printer. It is the kind of printer that is detected as parallel but has a USB cable. Manufacturer: EC Liner Model: EC Printer EC-PM-5890X Here's the website of the manufacturer: http://www.ecline.com.mx/ It seems that the computer is not detecting the printer directly, but the parallel connector (QinHeng Electronics). Here's all the information you asked in the comments above. If you need any more, please let me know: ------------------------------------ root@monsterbox:/# uname -a Linux monsterbox 3.8.0-23-generic #34-Ubuntu SMP Wed May 29 20:22:58 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux ------------------------------------ root@monsterbox:/# lsusb ... Bus 001 Device 005: ID 1a86:7584 QinHeng Electronics CH340S ... ------------------------------------ root@monsterbox:/# lsusb -v -d 1a86:7584 Bus 001 Device 005: ID 1a86:7584 QinHeng Electronics CH340S Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 8 idVendor 0x1a86 QinHeng Electronics idProduct 0x7584 CH340S bcdDevice 2.54 iManufacturer 0 iProduct 2 USB2.0-Print iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 32 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 96mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 7 Printer bInterfaceSubClass 1 Printer bInterfaceProtocol 2 Bidirectional iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x82 EP 2 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Device Status: 0x0000 (Bus Powered) ------------------------------------ root@monsterbox:/# lsmod | grep lp usblp 18111 0 ablk_helper 13597 1 aesni_intel cryptd 20373 3 ghash_clmulni_intel,aesni_intel,ablk_helper lpc_ich 17061 0 lp 17759 0 parport 46345 3 lp,ppdev,parport_pc ------------------------------------ network ipp14 network http network ipp network https direct hp network smb network beh network lpd network ipps network socket serial serial:/dev/ttyS0?baud=115200 direct hpfax direct usb://Unknown/Printer ------------------------------------ root@monsterbox:/# lpinfo -v network ipp14 network http network ipp network https direct hp network smb network beh network lpd network ipps network socket serial serial:/dev/ttyS0?baud=115200 direct hpfax direct usb://Unknown/Printer ------------------------------------ root@monsterbox:/# ls -l /dev/bus/usb/*/* crw-rw-r-- 1 root root 189, 0 Jun 11 00:05 /dev/bus/usb/001/001 crw-rw-r-- 1 root root 189, 1 Jun 11 00:05 /dev/bus/usb/001/002 crw-rw-r-- 1 root lp 189, 4 Jun 11 00:33 /dev/bus/usb/001/005 crw-rw-r-- 1 root root 189, 128 Jun 11 00:05 /dev/bus/usb/002/001 crw-rw-r-- 1 root root 189, 129 Jun 11 00:05 /dev/bus/usb/002/002 crw-rw-r-- 1 root root 189, 130 Jun 11 00:05 /dev/bus/usb/002/003 crw-rw-r-- 1 root root 189, 256 Jun 11 00:05 /dev/bus/usb/003/001 crw-rw-r-- 1 root root 189, 257 Jun 11 00:05 /dev/bus/usb/003/002 crw-rw-r-- 1 root root 189, 258 Jun 11 00:05 /dev/bus/usb/003/003 crw-rw-r-- 1 root root 189, 384 Jun 11 00:05 /dev/bus/usb/004/001 crw-rw-r-- 1 root root 189, 512 Jun 11 00:05 /dev/bus/usb/005/001 crw-rw-r-- 1 root root 189, 640 Jun 11 00:05 /dev/bus/usb/006/001 ------------------------------------ root@monsterbox:/# ls -l /dev/usb/lp* crw-rw---- 1 root lp 180, 2 Jun 11 00:33 /dev/usb/lp2 ------------------------------------ root@monsterbox:/# sudo /usr/lib/cups/backend/usb DEBUG: list_devices DEBUG: libusb_get_device_list=12 DEBUG2: Printer found with device ID: Device URI: usb://Unknown/Printer direct usb://Unknown/Printer "Unknown" "Unknown" "" "" ------------------------------------ root@monsterbox:/# ldd /usr/lib/cups/backend/usb | grep usb libusb-1.0.so.0 => /lib/x86_64-linux-gnu/libusb-1.0.so.0 (0x00007f56a93a9000) ------------------------------------ root@monsterbox:/# sudo modprobe usblp root@monsterbox:/# lsmod | grep usb usblp 18111 0 usb_storage 57204 1 usbhid 47074 0 hid 101002 2 hid_generic,usbhid root@monsterbox:/# sudo usb_printerid /dev/usb/lp2 GET_DEVICE_ID string: ��E��mg���dg��