Color LaserJet 2500, blue spots on print

My Color LaserJet 2500 is putting random blue spots on the pages. Looks like water drops on an inkjet printout.

I've printed the cleaning page and run it through, didn't make a difference. What's making the spots?

Here's how to do the cleaning since the Toolbox software doesn't work with Internet Explorer 8 or higher.

The original CD-ROM for the HP Color Laserjet 2500 contains "toolbox" software for checking the status of the printer, doing some basic diagnostics, updating the firmware, and running the printer's self cleaning process. (It stopped the horizontal streaking on mine!)

Problem is, the only way to get that Toolbox and status software is off an original HP CD-ROM. Only some updates for it can be downloaded from HP.

Also on the CD-ROM, uncompressed and ready to use, are the PRN files the Toolbox uses for calibration, cleaning and diagnostics, plus a couple of demo pages for wasting toner.

It's easy to use those to run the cleaning without having the Toolbox.

If the printer is connected by parallel port, enter this command from a command prompt. If your printer is on a different port number, change that part.

copy cleaning_page.prn /B LPT1

Remove all paper from the printer then place the printed page face down in tray 1 with the arrow pointed toward the printer.

Now enter this command.

copy clean_mode_page.prn /B LPT1

If the printer is connected to a USB port or a LAN, you must first share the printer from the computer you'll send the cleaning commands from. If you don't share the printer, the commands will return a network path not found error.

Open a command prompt and enter this. (Change HPColorL to your printer's share name.)

copy cleaning_page.prn /B \\127.0.0.1\HPColorL

Remove all paper from the printer then place the printed page face down in tray 1 with the arrow pointed toward the printer.

Now enter this. (Change HPColorL to your printer's share name.)

copy clean_mode_page.prn /B \\127.0.0.1\HPColorL