HP MFP Printers and Hard Drives Most of the mid-grade to high end HP LaserJet MFP’s operate, by design, from the firmware stored on its 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 boots-up from the firmware on the DIMM. The firmware DIMM provides only “partial functionality” that is, it will be able to print; however, it will not be able to copy, fax, or send an 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 from the hard disk drive. In all situations, with the exception of a disk failure, the firmware is loaded from the hard disk drive. 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 perform a firmware upgrade. (Call Tech support or visit http://www.laserpros.com/resourcecenter.asp for more information). Note: There are about a half dozen different styles / part numbers of hard drives used in HP MFP printers. The 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.