My hp laserjet m4345 mfp hasfirst 2 lights flashing and wont work

Cold reset
A cold reset unlocks menus that have been previously locked and resets all control panel menu items to the factory defaults. A cold reset does not clear the values in the service menu, such as the serial number and the page counts.
NOTE: Before performing a cold reset, print a menu map and a configuration page. Use the information on these pages to reset customer-specific settings.
CAUTION: All HP Jetdirect settings are also reset. Be sure to print a configuration page before performing a cold reset. Make note of the IP address that is listed on the Jetdirect configuration page. You will need to restore the IP address after performing a cold reset.
To perform a cold reset
1. Turn the MFP off and then on.
2. When the memory count appears on the control panel display, press and hold 6 until all three LEDs flash once and then stay on. This might take up to 20 seconds. wait until the machine display gives you the next option this may take upto 2 mins again
3. Press 3 four times until COLD RESET appears on the control panel display.
4. Press 6 one time. The MFP continues its initialization sequence.
a cold reset has been performed.

Please follow
-------------------------------------
To perform an NVRAM initialization
1. Turn the product off and then on.
2. When the memory count appears on the control-panel display, press and hold 3 until all three LEDs
flash once and then stay on. This might take up to 20 seconds.
3. Press and release 9, and then press and release Start.
4. Press and release 6.

Hejazi

49.XXXXX ERROR To continue turn off then on

A critical firmware error has occurred.
This type of error can be caused by invalid
print commands, corrupt data, or invalid
operations.
In some instances, electrical noise in the
cable can corrupt data during transmission
to the MFP. Other causes include poorquality
parallel cables, poor connections, or
specific software programs.
Sometimes, the formatter itself is at fault,
which is usually indicated by a 79 ERROR
message.

Follow this:

1 Turn the MFP off, and then turn the MFP on.
2 Upgrade the firmware.
3 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.
4 If the message persists when using different software programs and attempting specific print jobs,disconnect all of the cables that connect the MFP to the network or a computer.
5 Turn the MFP off.
6 Remove all DIMMs and flash-memory cards. Do not remove the firmware memory card that is in slot 1.
7 Remove all of the EIO devices.
8 Turn the MFP on.
9 If the error message disappears, reinstall each DIMM, flash-memory card, and EIO device individually, making sure to turn the MFP power off and then on again as you install each device.
10 Replace the component that caused the error message.
11 If the error persists, replace the formatter.

You've done everything but replace the formatter.
Can you look at the Event Log? Look for a 79.xxxx error. That is definately a formatter.
Is this a solid error, meaning does it appear when printer inits?
Remove the DIMMs and flash memory and network cable. And reinstall one by one until error reappears.
Do you have another 4345 that you can "borrow" a formatter from?

The pin for this specific machine should be 11434506.
If that doesn't work you must cold reset the machine.

Turn it off the machine.
Turn machine on hold 6 down until the memory count is done and all 3 lights are on release 6 and use 3 to arrow up to cold reset and press 6 "acts as the enter button"

FYI
3 works as arrow up
9 works as arrow down
6 works as the Enter button

[email protected]
To perform a cold reset
1 Turn the MFP off and then on.
2 When the memory count appears on the control-panel display, press and hold 6 until all three
LEDs flash once and then stay on. This might take up to 20 seconds.
3 Press 3 four times until COLD RESET appears on the control-panel display.
4 Press 6 one time. The MFP continues its initialization sequence.

Try performing a cold reset. press and hold "6" while booting and counting RAM. Release when all 3 led's are lit. Use "3" and "9" and navigate to "Cold Reset". Press 6 to enter.

Hi patricia_kin:
Hope this helps.

Cold reset
A cold reset unlocks menus that have been previously locked and resets all control-panel menu
items to the factory defaults. A cold reset does not clear the values in the service menu, such as the
serial number and the page counts.
NOTE Before performing a cold reset, print a menu map and a configuration page. See
Information pages. Use the information on these pages to reset customer-specific settings.
CAUTION All HP Jetdirect settings are also reset. Be sure to print a configuration page
before performing a cold reset. Make note of the IP address that is listed on the Jetdirect
configuration page. You will need to restore the IP address after performing a cold reset. See
Configuring and verifying an IP address.
To perform a cold reset
1 Turn the MFP off and then on.
2 When the memory count appears on the control-panel display, press and hold 6 until all three
LEDs flash once and then stay on. This might take up to 20 seconds.
3 Press 3 four times until COLD RESET appears on the control-panel display.
4 Press 6 one time. The MFP continues its initialization sequence.

To reset the maintenance-kit counter
1 Turn the MFP off and then on.
2 When the memory count appears on the control-panel display, press and hold 6 until all three
LEDs flash once and then stay on. (This might take up to 20 seconds.)
3 Release 6 and then press 3.
4 Press 6 to select NEW MAINTENANCE KIT.
5 The MFP completes its initialization sequence. The maintenance-kit counter is automatically reset.

count the times the green led flashes? and how it flashes that´s an error code for your problem. it can be the motherboard or power.