The device is locked into scan mode and shows scan error when the scan button is pushed.

SOURCE: HP LASERJET 3050 SCANNER: ERROR (not set up on pc).

Shirley,

If your still looking for a solution, or to those of you who have a similar problem, the following fixed my problem after trying to resolve the issue over the last year!!!!

I also received the "not set up on pc" message and tried re-installing the software numerous times.

Finally resorted to re-installing windows XP (because of this and other software glitches) and re-installed the Laserjet 3050 software again...but could not get the printer to install.

The problem was occuring while the software was asking to "plug in the usb cable", but would not complete the installation. It was not recognizing the device....the solution was to reset the laserjet 3050!!!!

to reset, push the "menu" button, < (left arrow), go to "service", "enter" button, > (right arrow), "Restore Defaults", "enter" button.
This should reset the factory defaults.

After this, I re-installed software, working!!!!!

Puas

SOURCE: Scanner failure

scanner failure, turn unit off and back on, does not help

SOURCE: HP LaserJet 3030 Message: Scanning error cannot connect

I had the same problem on XP and Vista and it turns out that if your don't have the HP Toolbox Running/starting up with pc this caused my problem. Once I lunched it to startup with I am able to scan using the Scan To Button on my Scanner.
-Cepedare

SOURCE: Our HP Color LaserJet CM 3530 will not scan or print

http://h20000.www2.hp.com/bizsupport/TechSupport/SupportTaskIndex.jsp?lang=en&cc=us&taskId=110&prodTypeId=18972&prodSeriesId=3709253
This is HP's troubleshooting site for your printer.If you can't find what you need there's a "contact HP"button where you can talk with a tech.Good Luck!

SOURCE: Scanner Locked Error

Scanner Lock -- a possible quicker fix

Instead of removing the entire glass plate, just remove the narrow glass strip to the far left. To do this, open the scanner top revealing the glass, and remove the philips screw centered on the left edge. With a thin flat-head screwdriver or even a good set of fingernails, you can then pry out the thin U-shaped plastic piece holding the glass strip in place.

When you remove the glass strip, you now have (narrow but sufficient) access to the scanner pulley and belt. Pull the spring-loaded pulley back towards your right to get some slack on the belt, then remove the belt from the pulley.

This frees up the scanner head, which you can now slide manually (by pulling gently on one end of the belt and giving slack on the other) to a center position well away from the scanner lock. When I first tried, I didn't move the scanner head far enough -- to the middle or beyond seems sufficient.

Push the scan lock to the full lock and then the full unlock position, to make sure it is now free.

Using fingers, screwdriver, and/or pliers, re-seat the belt on the pulley, once again using the freedom to move the spring-loaded pulley a bit to the right.

Replace the glass strip, plastic cover, and screw.

Power on the scanner. The error message should now be gone, and the scanner head should slide back to its resting position on startup (unless something is caught underneath, which was apparently the case for some who had this problem but was not the case for me). If the first power cycle doesn't do the trick, another power cycle might be helpful.

This approach eliminates the need to remove the scanner lid, control panel, and scanner glass.