Similiar Blank Display solution from HP web site:
HP LaserJet P3005 Printer Series - Blank Display
ISSUE: Printer has a blank display.
Check if the printer is connected directly into a wall outlet. If not directly connected, power off the printer and connect directly to wall outlet.
Disconnect any local or network connection from any device and keep the printer connected with the power cord cable.
Power cycle the printer. If the issue persists, continue with step 4. If the printer powers up to READY, perform the following steps:
Print a configuration page and check the firmware version. If the printer does not have the latest firmware version, upgrade the printers firmware. Click here to see the latest firmware available for your printer at www.hp.com/go/support
. Select Download driver and software (and firmware) and type in the product name or select the product from the product category list.
When the firmware upgrade is completed, power cycle the printer and print a configuration page again and check firmware date code, (it should change to the latest version) then power cycle the printer again.
If the printer powers up to READY, plug the local or network cable back in and print a Windows test page by printing from any application.
If the issue persists, continue with step 4 below.
Remove any additional memory DIMM installed (usually the LaserJet P3005N, DN and X come with a 32 MB memory DIMM installed), and any Internal EIO card or internal hard disk installed and then power cycle. If the issue persists, continue with the next step.
Perform a cold reset:
Turn the device off.
Turn the device on. When the memory count begins, press and hold the check button. Continue holding down the check button until all three device control-panel lights flash once and then remain on. This might take up to 10 seconds
After the message SELECT LANGUAGE appears on the display, press the arrow up or arrow down buttons until COLD RESET is highlighted.
Press the check button. The device performs a cold reset and then continues its power-on sequence.
If the issue persists, continue with the remaining steps.
If the printer powers up to READY, test the printer functionality by printing internal pages. Plug the local or network connection in and test the printer from the workstation.
If the issue persists without any internal device installed, the printer will require service.
Contact HP support.
Click here for information on contacting HP support at welcome.hp.com/country/us/en/wwcontact_us.html.
HP LaserJet P3005 Printer Series Blank Display