Model Focus: HP MFP Hard Drives Many mid to high end HP LaserJet MFP's operates by design, from the firmware stored on the hard disk drive. A "partial" firmware image also resides on the firmware DIMM installed into the ROM slot - or embedded on the product's Formatter PCA. If the hard disk drive should fail, the product will boot up from the firmware on the DIMM but with only "partial functionality". The printer will print but will not copy, fax, or send e-mail. Included with the firmware image on the formatter's ROM DIMM is a boot loader. During the power up process, the boot loader instructions tell the MFP to load the firmware image from either the ROM DIMM, or the hard disk drive. Thus, the firmware is loaded from the hard disk drive, with the exception of a disk failure. When the hard disk drive is replaced, a firmware image must be installed onto the hard disk drive. The best results have been to perform a "disk initialization" and then a firmware upgrade. Note: There are about a half dozen different styles / part numbers of hard drives used in HP MFP printers. J6054-69051 - 40 GB EIO Hard Disk will operate in all of them in place of the original. *This Tech Tip is contributed by Laser Pros. Visit their website www.LaserPros.com or email any question to marketing@laserpros.com.