NOT WORKING i requst sir i am using the 3940 printer but presently this priter paper jam OR the indication bulb is the bliking continuley. what is the problem si but paper canot put in the printer but can display pape jam .so please solution &one moe requst sir pls give me the service engineer in the my locality, my compny address PAC COMPUTERS 606,MAITHRI VANAM. S.R.NAGAR HYDERABAD (A.P). INDIA.500038. PLS CONTACT MY NO SIR :+91-9966221075

Make sure that all of the doors are shut, all trays are in properly, shut off printer, unplug from the wall. Press the power button while unplugged to clear any residual power. Wait a couple of minutes, plug in, and power up the printer. Good luck!!

In my experience, i believe that you still have a small piece of paper stuck in the machine.

Please follow the directions in the link below:
The Power light ( ) might blink (flash) or be off. A blinking Power light indicates that the product requires maintenance, or is in an error state.

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=110&prodSeriesId=445475&prodTypeId=18972&prodSeriesId=445475&objectID=c01082964

From your description,it seems that other material present inside your printer and blocking the paper path. Sometimes,broken paper feeder indicates the same way. I recommend you to bring your printer to the nearest service center unless you are quit familiar with assembly and reassembly of this printer.

Source:
Printer Clinic
Download Instant Manual

Hello there
i know you have cleared the jam but i would go back and really look closley at the paper path and the internals a small piece off of a paper can cause this to claim it has a jam also if you turn off the printer and use canned air to blow out the whole insides this will help too also clean offf any lenses with a eyeglass cleaner ok ?
best regards mike

I have a HP Deskjet 3940 printer. And similarly to this problem here I had a paper jam that would not clear, despite removing all the paper that was stuck in it, and following all 4 steps stated on the HP website. Such as taking the back cover off and blowing dust away and turning it off and on, etc.

None of these steps worked for me and consequently I couldnt get any new jobs to print - kept saying 'paper jam'. I was about to head down the shop to buy a new printer when i tried one last thing, which HAS fixed the problem!

I put in a large stack of paper onto the feeder. and then pushed it forcefully in and out repeatedly. To my amazement this has solved the paper jam. As a very last resort, might be worth trying this?

do not load the printer with lots of papers... reduce them...

Sounds like you have a paper jam somewhere. Open up the printer and look for some paper. If the page is still in the machine, sometimes you can gently pull ever so slowly and finish getting the paper out of the machine. Power cycle the machine and if it was a jam, you should be fine.

paper out sensor not working it's possible