72 Chapter 4POST Beep CodesNo beep, power indicator turns on, the LCDscreen is blank, but you can view POSTwhen connected to an external CRT.Reconnect the LCD-CCD cable.LCD-CCD cableInverter boardLCD panelSystem boardNo beep, power indicator turns on and ablinking cursor appears on screen duringPOST.Ensure every internal cables are properly and securelyconnected.System boardNo beep during POST but system runscorrectly.SpeakerSystem boardCode Beeps POST Routine Description02h Verify Real Mode03h Disable Non-Maskable Interrupt (NMI)04h Get CPU type06h Initialize system hardware08h Initialize chipset with initial POST values09h Set IN POST flag0Ah Initialize CPU registers0Bh Enable CPU cache0Ch Initialize caches to initial POST values0Eh Initialize I/O component0Fh Initialize the local bus IDE10h Initialize Power Management11h Load alternate registers with initial POSTvalues12h Restore CPU control word during warmboot13h Initialize PCI Bus Mastering devices14h Initialize keyboard controller16h 1-2-2-3 BIOS ROM checksum17h Initialize cache before memory autosize18h 8254 timer initialization1Ah 8237 DMA controller initialization1Ch Reset Programmable Interrupt Controller20h 1-3-1-1 Test DRAM refresh22h 1-3-1-3 Test 8742 Keyboard Controller24h Set ES segment register to 4 GB26h Enable A20 line28h Autosize DRAM29h Initialize POST Memory Manager2Ah Clear 215 KB base RAM2Ch 1-3-4-1 RAM failure on address line xxxxError Message FRU/Action in Sequence
