[Solved] - Canon ImageCLASS MF6550 - change reg'd size -> common settings -> change papersize cassette 1 : LTR

This MSG kept on displaying on the LCD along with the red flashing light and a sound when a print job was given to MF6550. On top of that every time the cassette was arraged and placed correctly or left deck was checked for blocked papers and closed the same page was printed everytime. The manual of MF6550 had no solution to such scenario.
Few googl'ing gave a link/pdf on "How to fix the check paper size error msg for MF5600/MF5700" series laser multifunctional.
The panels were different but it did the work.

Canon ImageClass MF6550

Carrying out the following step didn't solve the problem (as indicated by the err msg)

Check the paper settings on the Printer

For Paper Cassette the default settings are <Plain paper> and <LTR>. When you place other types of paper, the steps to be followed are

•  Press [Additional Functions] (button 2)
•  Confirm that <Common settings> is displayed, then press [Ok] (button 4)
•  Press [-] or [+] to select <select paper type>, then press [OK] (button 3,4,5)
•  Confirm that <Cassette 1> is displayed, then press [OK]
•  Press [-] or [+] to select the paper type, then press [OK]
•  Confirm that <Reg. Paper size> is displayed, then press [OK]
•  Confirm that <Cassette 1> is displayed, then press [OK]
•  Press [-] or [+] to select the paper size, then press [OK]
•  Press [STOP] to return to standby mode

The below given step did the work

Apart from removing the printjob from desktop

Removing jobs from the print Queue (logging what could be recalled)

•  Press [System Monitor] (Button 6)
•  Press  [(-)] or [(+)] to select <Print Status> (Button 5 or 3)
•  Press OK (Button 4)
•  Press OK to delete the Print Job

ref:- Manual of the MF6550 + checkpapererror.pdf of MF5700

[Solved] - HP F4488 not printing - /usr/lib/cups/backend/hp failed

Happen to remove my color cartridge and test out only with my black cartridge. It worked the first time but later on every time when I selected the printer with the respective application beside the deskjet F4400 - /usr/lib/cups/backend/hp failed was displayed. I tried stopping and restarting the cupsys daemon
/etc/init.d/cupsys.d stop
/etc/init.d/cupsys.d start

I couldn't get it started so following the instruction at http://chenjie66.wordpress.com/2011/03/26/usrlibcupsbackendhp-failed/ which did work.

I don't know whether the gui equivalent of such resolution is available or not.
like
system->adminstration->printing

user@dell-laptop:~$ sudo cat /etc/cups/printers.conf
# Printer configuration file for CUPS v1.3.7
# Written by cupsd on 2011-12-24 09:50
<Printer Deskjet_F4400>
Info Deskjet_F4400
DeviceURI hp:/usb/Deskjet_F4400_series?serial=CN03JC330405C5

State Stopped
StateMessage /usr/lib/cups/backend/hp failed

StateTime 1324700406
Accepting Yes
Shared Yes
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
OpPolicy default
ErrorPolicy retry-job
</Printer>
<Printer Deskjet_F4400_series>
Info HP Deskjet F4400 series
DeviceURI hp:/usb/Deskjet_F4400_series?serial=CN03JC330405C5
State Idle
StateTime 1280592353
Accepting Yes
Shared Yes
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
OpPolicy default
ErrorPolicy retry-job
</Printer>
<Printer PDF>
Info PDF
DeviceURI cups-pdf:/
State Idle
StateTime 1214886871
Accepting Yes
Shared No
JobSheets none none
QuotaPeriod 0
PageLimit 0
KLimit 0
OpPolicy default
ErrorPolicy retry-job
</Printer>
user@dell-laptop:~$

change State to Idle
 and
remove StateMessage and the printer starts to work normally

other outputs at the time of failed service

user@dell-laptop:~$ sudo cat /var/log/cups/error_log
E [31/Jul/2010:21:35:53 +0530] CUPS-Add-Modify-Printer: Unauthorized
E [31/Jul/2010:22:58:36 +0530] CUPS-Add-Modify-Printer: Unauthorized
E [01/Dec/2010:17:09:30 +0530] PID 8565 (/usr/lib/cups/backend/hp) stopped with status 4!
E [01/Dec/2010:17:18:09 +0530] PID 9535 (/usr/lib/cups/backend/hp) stopped with status 4!
E [02/Dec/2010:11:50:52 +0530] PID 6337 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:06:14:49 +0530] PID 14855 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:06:15:19 +0530] PID 14883 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:06:20:34 +0530] PID 7016 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:42:25 +0530] PID 6329 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:42:27 +0530] PID 6746 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:47:37 +0530] PID 8042 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:47:39 +0530] PID 8047 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:52:49 +0530] PID 8267 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:52:50 +0530] PID 8272 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:58:01 +0530] PID 8581 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:07:58:02 +0530] PID 8586 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:08:03:13 +0530] PID 8799 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:08:03:14 +0530] [Job 20] Canceling job since it could not be sent after 5 tries.
E [10/Mar/2011:08:03:14 +0530] PID 8804 (/usr/lib/cups/backend/hp) stopped with status 1!
E [10/Mar/2011:08:03:15 +0530] [Job 22] Canceling job since it could not be sent after 5 tries.
E [24/Dec/2011:09:50:05 +0530] PID 9822 (/usr/lib/cups/backend/hp) stopped with status 4!

dmesg

usblp0: removed
[  373.784336] usb 7-1: USB disconnect, address 2
[  397.575185] usb 7-1: new high speed USB device using ehci_hcd and address 3
[  397.709008] usb 7-1: configuration #1 chosen from 1 choice
[  397.709980] usblp0: USB Bidirectional printer dev 3 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7711
[  411.401418] usb 7-1: USB disconnect, address 3
[  411.401999] usblp0: removed
[  429.409997] usb 7-1: new high speed USB device using ehci_hcd and address 4
[  429.543896] usb 7-1: configuration #1 chosen from 1 choice
[  429.545109] usblp0: USB Bidirectional printer dev 4 if 1 alt 0 proto 2 vid 0x03F0 pid 0x7711
[  435.642008] usblp0: removed
[  452.488867] usb 7-1: USB disconnect, address 4

The result of a working printer with almost all the indicator blinking as if it won't work but IT WORKS