On power up, unit begins to go thru calibration. Then freezes up. Display remains blank. Clicking is heard from scanner unit. Scanner bulb blinks on one end. Unplugging sometimes resets to the point it will begin the calibration. Otherwise, it just clicks on powerup. I've removed the bed glass and slid the scanner to the home position. This allows it to begin calibration, but it always ends up frozen and clicking. No error message display.

The H4 code indicates the fuser may have blown the thermistor. It also could be a false error code. Try this series to clear the error and if it returns, then you'll know for sure the fuser is the culprit. To reset press the following buttons:

1. Press this sequence: CLR-Exposure-CLR-Exposure
2. The display will go blank
3. enter "14", press "PRNT"
4. Press "CLR" several times to exit.

Give that a try and good luck.

paul here i am, what happened, you suddenly ended our session, do you still have the script? we can continue it there if you want. just watch out for my reply.

If the equipment shows the message "Scanner bulb warming up" and not initializes, look resolve:
Well have to clean the scanner assembly. Contains about 4-5 mirrors. It is very difficult to disassemble, careful to clean.

From here you can get service manual. There are 6 parts. put them all in a folder and a unzipp the first.
http://eserviceinfo.com/downloadsm/34029/HP_2820,2830,2840.html

Good luck!

The Calibration of the scanner and calibration of the monitor - a complex process. Prcess requiring special equipment and experienced specialist. Not advantageously buy high-priced equipment for Calibration of its one scanner and monitor. If work high skilled, you it is necessary to return in service for calibration if you want this execute themselves, recommend to build apart monitor on test list, but then on test table by means of regulations adjusting the scanner on colour and density of the scene to build scanner

You have a bad scanner bulb

Sharp AL-1553 code


E7 03 Scanner position error 04 Exposure lamp blown 05 CCD calibration error 12 White level calibration error 14 Main board malfunction 15 Exposure lamp blown L1 00 Scanner position error L3 00 Scanner position error L4 01 Main motor drive overloaded L6 10 Polygon mirror motor not up to speed H2 00 Fusing unit temperature error H3 00 Overheated fusing unit H4 00 The fusing unit doesn't heat up U2 01 Counter error 04 EPROM error CH blinking Dev unit is not properly installed

I Have A HP Laserjet 2820 on power up went through to scanner bulb warming up then made a clicking noise comming from scanner unit it was trying to escape the case. if this is the same as yours the problem is that the scanner unit can't find the home position strip mounted betweent the gray case wide piece right hand side as you look down on scanner unit with lid up & the top of the scanner glass inside the scanner unit to get to it you must remove top section of the scanner unit & cleean underside of scanner glass please E-mail me if you want full instruction.

I had a similar problem, the scanner bar was stuck to the far left side. Here's how I fixed it:

1)Unplug the printer, disconnect any cables/phone lines to it.
2)Lift up the entire scanner bed housing(you will see the printer ink cartridges).
3)Locate the access patch (approx 1 cm x 1 cm square) along the left edge of the scanner bed housing(this is the side that closes in, next to the keypad buttons).
4)Using a small knife blade, peel off the patch from the corners and edges(it's sticky. Save it, you can stick it back over the hole when you're done).
5)Stick a pen through the access hole, and push the scanner bar to the right, approximately 2-3 inches.
6)Now, close the scanner housing, plug in the printer, and power it on.

It should reset and re-calibrate the scanner bar. If it doesn't, repeat steps 5) and 6) a couple times, until the printer correctly performs calibration. Then, you can put the sticky patch back over the hole, and you're ready to go. Hope this helps!

P 4

Bad Solder Conns from the Ribbon to the Main Board can Cause this Ck it Let me Know if this Helps ttech