HP Laserjet 4345MFP scan to folder is too light.

Try this

Check ADF unit (automatic document feeder) working condition.
For diagnoses : Insert few paper(ex:10papers) in ADF unit & do copying, if UR succeed in copying, ADF is working well.. If not check the fault.
HP M4345 facilitated with digital sending option., for configuring digital sending U need to create shared folder with fully permissions in system. Better visit hp site or google to know about how to create folder.. You can do multiple scanning once configuration completed successfully..for more info visit:
http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay?javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&javax.portlet.prp_ba847bafb2a2d782fcbb0710b053ce01=wsrp-navigationalState%3DdocId%253Demr_na-c02720194-2%257CdocLocale%253D%257CcalledBy%253D&javax.portlet.tpst=ba847bafb2a2d782fcbb0710b053ce01&ac.admitted=1409945500358.876444892.492883150

you can scan from adobe photoshop

Take copy with default settings, if quality is poor, need to clean inner parts like reflecting glass, engine reflector of optical scanner assm(CCD)..& flat bed glasses both sides.
Note: with out proper knowledge pl don't open this printer..

Mr. Agarwal
you have to turn off the duplex scanning option under copy settings this will solve the issue
You can go to settings and look for Copy setup or copy settings i dont remember well but you get an option of DUPLEX COPY or DUPLEX SCAN you have to turn off this.
DO RATE MY SOLUTION PLEASE
Saleem

install printer Driver
change print port to "Virtual printer port for usb"
use usb line
down load the right firmware .rfu file
in CMD mode,type:
copy /b firmwarefilename.rfu \\pc name\printer name
waitting
it will be down
good luck!

Making multiple copies from one original thru DH, all copies come out good. Having one original and making mutiple copies, first copy comes out find and the rest comes out light. This is cause by the circut board on the optical assembly. Part # IR4041K121NI

BLANK or BLACK?, if it's Black, clean the SCANNER GLASS.

Although this problem would normally show as a black line on the copy, it's quite possible that there is something white (i.e. a piece of tape or paper) stuck on the scanner where the page feed passes through. Clean this area carefully with a soft cloth.

It sounds like a driver problem. Try replacing the driver for this printer on the printers folder, using the HP LaserJet Series II. With this driver, try again the PDF file and see if it prints correctly.