HP LaserJet Pro 300 Service Manual - Page 98

Formatter PCA Special considerations WARNING! Do not install a replacement formatter PCA and DC controller PCA at the same time. The formatter PCA and the DC controller PCA store important product configuration information (NVRAM data) that is lost if both PCAs are replaced at the same time. When the product power is turned on, the DC controller restores the NVRAM data on the replacement formatter. Replacing both the formatter and the DC controller at the same time will result in severe print-quality problems. NOTE: The base model does not have a fax card installed. Replacing the formatter PCA before the DC controller PCA Use the following procedure if you need to install a replacement formatter PCA and a replacement DC controller. NOTE: If you are only installing a replacement formatter PCA, go to Remove the formatter PCA on page 74. 1. Install a replacement formatter PCA. 2. Turn the product on, and wait for the print-cartridge volume indicators to appear on the controlpanel display. NOTE: This allows important product information to be written to the replacement formatter PCA. 3. Turn the product off. 4. Install a replacement DC controller. See DC controller PCA on page 76. 5. Turn the product on. Remove the formatter PCA CAUTION: Do not bend or fold the flat flexible cables (FFCs) during removal or installation. Also, do not straighten prefolds in the FFCs. You must ensure that all FFCs are fully seated in their connectors. Failure to fully seat an FFC into a connector can cause a short circuit in a PCA. Some parts are sensitive to electrostatic discharge (ESD). Always perform service work at an ESDprotected workstation or mat. If an ESD workstation or mat is not available, ground yourself by touching the sheet-metal chassis before touching an ESD-sensitive part. 1. Remove the right cover. See Right cover on page 21. 74 Chapter 1 Removal and replacement ENWW