POST error codesEach time you power-on the system, it performs a series of tests that check the operation of the systemand some options. This series of tests is called the Power-On Self-Test, or POST. POST does the followingoperations.• Checks some basic system-board operations• Checks the memory operation• Starts the video operation• Verifies that the boot drive is workingIf the POST detects a problem, an error message appears on the screen. A single problem can cause severalerror messages to appear. When you correct the cause of the first error message, the other error messagesprobably will not appear on the screen the next time you turn on the system.POST Error Message Description/ActionCMOS battery failed The CMOS battery is no longer functional.Replace the battery.CMOS checksum error - defaults loaded Checksum of CMOS is incorrect.The computer loads the default configuration settings.This error might indicate that CMOS has become corruptdue to a weak CMOS battery.CPU at nnnn nnnn is the running speed of the microprocessor.Press Esc to skip memory test Pressing Esc skips the full memory testHARD DISK INSTALL FAILURE Cannot find or initialize the hard disk drive controller orthe drive.Make sure the hard disk drive is correctly installed.If no hard disk drives are installed, make sure the harddisk drive selection in Setup is set to NONE.Keyboard error or no keyboard present Cannot initialize the keyboard.Make sure the keyboard is properly connected to thecomputer and that no keys are held pressed during POST.To purposely configure the computer without a keyboard,set the error halt condition in Setup to HALT ON ALL, BUTKEYBOARD. The BIOS then ignores the missing keyboardduring POST.Memory Test: This message displays during a full memory test, countingdown the memory areas being tested.Memory test fail If POST detects an error during memory testing, additionalinformation appears. This information gives specificsabout the type and location of the memory error.70 ThinkStation Hardware Maintenance Manual