Printer problem my HP laser jet 4350n printer turns on but the display screen is blank

just happend, today, yesterday was ok, same setup?
or just got this from a garage sale and ...
or found it or barrowed it or >? tell the story please.
no PC stated
no OS stated (windows what?)
to run a printer on USB the printer needs to be reset first.
to USB mode, this is covered in the manual, lost that?
the USB port needs to be working , try them all/?
the HP software needs to be loaded too.
omg its 14 years old today. click software and then click change.
then pick your UNSTATED OS,in the huge list of operating systems this printer supports even up to w10

https://support.hp.com/us-en/product/hp-laserjet-4350-printer-series/412160/model/412162/manuals

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

Could be bad Control Panel or bad Formatter.Start with the Control Panel, it's cheaper.1st make sure the cable is attached to it.

Did you try those drivers http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?lang=en&cc=us&prodTypeId=18972&prodSeriesId=412160&prodNameId=412171&swEnvOID=228&swLang=8&mode=2&taskId=135&swItem=ja-45284-10

laser jet printer oprated with positive or negative charge by charging ruler so please chek it.

i am an expert in a different catagory,...
but i read your problem accidently and i had the same problem with my laser jet..
check the order list (in you PC screen in the right end of the START bar there is a little printer ...)click on it
and if you find a printing order of a blank page delete it...if not
then its not the same problem and am sorry i can't help any more..

sir there will be no ink your printer please check and reply again

Hp says you have a bad scanner unit(laser unit) or DC controller, but first reseat all your connectors on your scanner unit(laser) and DC controller. Your scanner is located under the top cover and the DC controller is located behind the right cover. If the problem still persist replace the scanner first.

If the printer control panel is blank when you turn on the printer, check the following items.
1 Make sure that the printer is plugged into an active electrical outlet receptacle that delivers the
correct voltage.
2 Make sure that the on/off switch is in the on position.
3 Make sure that the fan runs briefly, which indicates that the power supply is operational.
4 Make sure that the control-panel display wire-harness is connected. See the hint in the
procedure for Top cover.
5 Remove any HP Jetdirect or other EIO cards, and then try to turn the printer on again