36Using Support ToolsAlert! Previous attempts at booting this systemhave failed at checkpoint [nnnn]. For helpin resolving this problem, please note thischeckpoint and contact Dell TechnicalSupport — The computer failed to completethe boot routine three consecutive times forthe same error. Contact Dell for assistance (see“Contacting Dell” on page 55).CMOS checksum error — Possible systemboard failure or coin‑cell battery low.Battery needs replacement. See the ServiceManual at support.dell.com/manuals or contactDell for assistance (see “Contacting Dell” onpage 55).CPU fan failure — CPU fan has failed. CPUfan needs replacement. See the Service Manualat support.dell.com/manuals.System fan failure — System fan has failed.System fan needs replacement. See the ServiceManual at support.dell.com/manuals.Hard-disk drive failure — Possible hard‑diskdrive failure during HDD POST. Contact Dell forassistance (see “Contacting Dell” on page 55).Hard-disk drive read failure — Possiblehard‑disk drive failure during HDD boot test.Contact Dell for assistance (see “ContactingDell” on page 55).Keyboard failure — Replace keyboard or checkthe cable for loose connection.No boot device available — No bootablepartition on hard drive, the hard drive cable isloose, or no bootable device exists.If the hard drive is your boot device, ensure•that the cables are connected and that thedrive is installed properly and partitioned asa boot device.Enter system setup and ensure that the•boot sequence information is correct.See theService Manual atsupport.dell.com/manuals.