The error "49. FF05 SERVICE ERROR" is displayed on

49.FF04 - in older 4xxx printer it mneans a firmware error - try to do:
1. cold reset
2. updaete firmware
3. remove network card from printer and instert it back - or try to turn printer on without it.
4. reinstall the formatter - phisical connection may be not good ( formater is a "cage" that the networc card is inserted)
go to http://www.hp.com for more information

there is nothing wrong with your printer!! it is a connunication issue from the computer to the printer... cancel the document that you tried printing and try reprinting it again.. to clear the error remove the USB cable or Network cable then turn off the printer.. then back ON while the printer is in the ready state re attache the USB or Network cable and reprint the document :-)

I’m happy to help further over the phone at https://www.6ya.com/expert/ron_9356d26241d4cbf7

ISSUE: A 49.x service error appears on the HP Color LaserJet 4500 or 4550 printers display, and other unexpected errors may be displayed such as:

1. Turn the printer off, and then turn it on again. If the 49 error clears, proceed to Step 9.
2. If the 49 error returns turn the power off, unplug the power cable, disconnect all network cables, and remove the HP Jetdirect card, which is located on the formatter, (see Figure 1 for location), or any third-party devices, if installed.
3. Wait at least 30 seconds before plugging the printer back in directly to a wall outlet. Do not plug the printer into a power strip or a surge protector.
4. Turn the printer on, using a cold reset. If the 49 error returns, turn the power off, and unplug the printer. Remove the formatter, and check that the parallel I/O board is firmly installed on the formatter board.
   NOTE: To perform a cold reset, turn the printer off, and hold down the GO button while turning the printer back on. Remember to remove the Jetdirect card (if installed) before performing a cold reset. (The Jetdirect card is located on the formatter).

This is a common issue with HP printers, usually caused by updated programs such as Adobe Acrobat.

Here is a link to a tip I wrote on how to solve this problem. click here

A 49 error on an HP printer is caused by the printer receiving a commmand it does not understand. It is the computer equivalent of "huh?" The first step to fixing this is to ensure that you have the most current firmware installed for the printer. Curent version is 02.120.3. To find what is installed, restart printer to clear the 49 error and then printer a configuration page. On the upper left hand side of the config page you will find the firmware revision listed. If it is not 02.120.3 then follow instructions below. You can print a config sheet by using the up or down arrows to change the menus until it displays information. Press checkmark and then on the next menu use the up/down arrow till you find configuration sheet and press checkmark again. You may need to ensure that there are no print jobs pending so that the printer does not have another 49 error while you are trying to do this.

Firmware upgrade instructions:

Click here to access HP site where you will find the lastest firmware revision. If you are using Windows, download the first option which is the EASY INSTALL. Run the file once downloaded and it will automatically start and confirm which printer you want to upgrade.

i think this caused by your windows is not genuine

Verify is there DIMM in slot?.. replace with same part no.If no DIMM in slot replace formatter.

I have been through the service manual, and googled the FF05 error. I could not find it anywhere except with a 49 in front of it. 49.FF05.
Power off the printer and then loosen the two screws for the JetDirect card. Pull the card out about 1/2". Now power on the printer and see if the error comes back. If it doesn't, print out a config sheet. If still no error power off and plug in the jetdirect, power on and if the error comes back, get a new jetdirect card.
Now if you get the error with the jetdirect removed, remove the rear left side cover(as you stand at the rear of the printer. This will expose the formatter. Open the formatter door. There is a latch at the front of the formatter, pull it out and the door will swing open. See if you can see a memory DIMM in there. If yes, power off and then remove the DIMM or DIMMs(depending on your memory size). Power up and see if the error comes back. If yes, there is one more thing to try - NVRAM initialization before replacing the formatter. DIMMs arn't $500.
Get back to me after you try the stuff mentioned above, if you still get the error.

A critical firmware error has
occurred.
Try following these steps -
1. Press CANCEL JOB to clear the
print job from the printer
memory.
2. Turn the printer off, and then
turn the printer on again.
3. Go to http: www.hp.com/
support/lj2410, www.hp.com/
support/lj2420, or
www.hp.com/support/lj2430.
Click Download Drivers and
Software. Check for the
latest firmware image version
at the bottom of the page. If
this firmware image is newer
than the one installed on the
printer and the printer can
receive a firmware update,
download the newer firmware
upgrade. Not all printer
models can receive firmware
upgrades.
4. Try printing a job from a
different software program. If
the job prints, go back to the
first program and try printing a
different file. If the message
appears only with a certain
software program or print job,
contact the software vendor
for assistance.
1. After performing the actions
listed in the preceding item, if
the message persists when
using different software
programs and attempting
specific print jobs, disconnect
all cables that connect the
printer to the network or a
computer.
2. Turn the printer off.
3. Remove all memory DIMMs
or third-party DIMMs from the
printer. (Do not remove the
firmware DIMM in slot J1.)
4. Remove all of the
EIO devices from the printer.
5. Turn the printer on.
6. If the error message
disappears, reinstall
each DIMM and EIO device
individually, making sure to
turn the printer off and then
on again as you install each
device. To replace a DIMM,
see.
7. Replace the DIMM or
EIO device that caused the
error message.
8. Remember to reconnect all of
the cables that connect the
printer to the network or
computer.
9. If this error message persists,
replace the firmware DIMM.
10. Replace the formatter

first upgrade the firmware from HP page
second try to print from diferent port
third if the 2 other solutions dont work for you, replace the formatter.