20 Most Recent HP LaserJet 4L Printer - Page 8 Questions & Answers

The fuses are located on the DC Controller (main bottom board). Getting to the DC Controller Board on a 4L printer is a very significant disassembly. Best left for a pro but if you really want to do it, I have attached below a link to a scanned copy of the service manual. Please keep in mind that the scanned copy is not a nice fresh PDF as most manuals as the 4L was made in 1994 and HP has physically scanned the printed manual for distribution. Just look up the removal and replacement of the DC Controller Board. Once removed, the fuses are glass buss style, readily available at any Radio Shack.

Gotta love that old technology.

Hope this helps you. :)

http://www.feedroller.com/Store/Service%20Manual/LASERJET%204L,%204ML,%204P,%204MP%20Service%20Manual.pdf

Remove the tray and then remove the screw shown in the picture.
Remove the peice as shown in the photo below to reveal the feed wheel beneath.

Open the top cover and remove the screw just to the left of the white/clear section shown in the photo below.

The smoked plastic peice will unclip from the fron end by grasping the inner most edge and gently rocking up and inward. This will reveal the entire feed wheel.

Clean the entire wheel in the above photo with a damp (Not soaking, just damp) cloth. The wheel will turn making a clicking sound (top inward) allowing you to clean it entirely. Also clean the obligue roller (1st part removed) with a damp cloth and blowing out.

Reassemble as you just took it apart. Pay close attention to the smoked plastic peice that it gets front clipped properly back into place. Don't force it. It will all go back together relatively easy.

That should help eliminate a lot of your jamming issues.

Hope the above helps you. :)

What you actually hav is a cracked gear on the main motor. It shows up when you install the cartridge because it requires more torque to drive the cartridge. Remove the top cover, the side formater board. There is 1 screw on the side and 2 on the top that hold in the motor. The motor with the gear attached is available from Dale at Seattle Platen, 1-800-221-2388. Gear only isn't available. Cost is around $25.00.

here is a basic guide

here is some PJL commands http://www.hpinfo.cz/Data/PCL&PJL/HPPJL.pdf

and hp FAQ LINK

and you can buy it LINK

specs

I didn't think it would be that hard!!!!!!!! Just wasted half hour so please rate at least

After I did the calibrate it stopped giving me this message. I turned off everything and as they say: shut down and turn on again.

One possibility might be the transfer roller. Make sure it is secured. It's probably only getting a charge on one half of the roller.

Good. Usually that error is cause by a bad data signal comming in from the printer cable. It should be replaced to get rid of the problem.

Did this occur suddenly or over a period of time it got worse?

Did it happen after a jam or other activity like replacing the drum?

Please try to reinstall your driver.

time to give it a decent burial..parts on those old 4L's are mostly drawn from others that are no longer functioning..

maybe you ought to have an HP wake, and a decent burial?

at any rate..that sounds like a power supply board went zonko..

With printer unplugged, open lid and pull paper out by hand. Depending on where paper is jammed, you may have to lift out toner cartridge first. Be careful when pulling out paper, especially if paper is crumpled up. Sometimes it is easier to pull paper from back of printer as if it were continuing to print, and others it is easier to pull reverse from the front.

Try reseating the print cartridge if this does not work try a new print cartridge the problem seams like your primary charge failure.
If you require more help please get back to me
Thank You

check the internal roller ( central ) easy to remove . clean with alcohol's dry put it back ... (robber couvred)

try with re-installing the driver and see. bye

Try lowering the toner density using the printing software or the printer menu.

I don't think there is one.

There are several things in the front that could be making that noise.The transfer roller,paper guide/top ublique roller and front obligue roller which is on the left side front. It is hard to say. I guess the printer is printing OK. If not what is the printer doing? Do you get any paper jams? Printing light? Can you rub the print off the paper? Any labels stuck? Please answer questions so I can help you. My guess is a roller problem. Which one is hard to say since I can't hear the printer myself.

Try feeding using bypass, probally worn/dirty/broke paper cassette paper feed roller having trouble feeding the paper in.

Try and push the blue button after clearing the jam.

Replace the power switch. A fairly standard switch type. You may get one off ebay or similar site. If push came to shove, you could just replace the power input assy.