v Follow the suggested actions in the order in which they are listed in the Action column until the problemis solved.v See Chapter 3, “Parts listing, System x3800 Type 8866,” on page 107 to determine which components arecustomer replaceable units (CRU) and which components are field replaceable units (FRU).v If an action step is preceded by “(Trained service technician only),” that step must be performed only by atrained service technician.Error code Description Action405-xxx-00n No good link! Check loopback plug. 1. Make sure that the loopback plug is a gigabitloopback plug (see “Solving Ethernet controllerproblems” on page 103).2. Check for any loose connections between theloopback plug and the Ethernet connector.Real Time DiagnosticsReal Time Diagnostics can help you diagnose problems in certain devices while theoperating system is running, to prevent and minimize server downtime.For more information and to download Real Time Diagnostics, go tohttp://www-1.ibm.com/support/docview.wss?uid=psg1MIGR-50681.Recovering from a BIOS update failureThe server has an advanced recovery feature that will automatically switch to abackup BIOS page if the BIOS code in the server has become damaged, such asfrom a power failure during an update.The flash memory of the server consists of a primary page and a backup page. Ifthe BIOS code in the primary page is damaged, the baseboard managementcontroller will detect the error and automatically switch to the backup page to startthe server. If this happens, a POST message Booted from backup POST/BIOS imageis displayed. The backup page version might not be the same version as theprimary page version.You can then recover or restore the original primary page BIOS by using a BIOSflash diskette.To recover the BIOS code and restore the server operation to the primary page,complete the following steps:1. Download the latest version of the BIOS code from http://www.ibm.com/servers/eserver/support/xseries/index.html.2. Update the BIOS code, following the instructions that come with the update filethat you downloaded. This will automatically restore and update the primarypage.3. Restart the server.If that procedure fails, the server might not restart correctly or might not displayvideo. To manually restore the BIOS code, complete the following steps:1. Read the safety information that begins on page vii and “Handlingstatic-sensitive devices” on page 115.2. Turn off the server and peripheral devices and disconnect all external cablesand power cords; then, remove the cover.78 IBM System x3800 Type 8866: Problem Determination and Service Guide
