Compaq 1200US Presario Select 1200 Series Maintenance and Service Guide - Page 17

Maintenance & Service Guide Presario Series Models: 1246, 1247, 1277, 1278, and 1279 | Home Page | Notice | Preface | Product Description | Troubleshooting Illustrated Parts Catalog | Removal & Replacement Procedures | Specifications Pin Assignments | Battery Pack Operations Troubleshooting Power-On Self Test (POST) Running POST To run POST, turn off the computer. Then turn on the computer. If POST does not detect any errors, the computer will not beep. This indicates successful completion of POST test. POST has run successfully and boots from the hard drive (or from a bootable diskette if one is installed in the diskette drive). If POST detects errors, the errors are indicated by screen and/or audible messages. Refer to "Power-On Self-Test (POST) Codes" in the tables for a list of POST codes and their relevant descriptions. If the system is not functioning well enough to run POST, or if the display is not NOTE: functioning well enough to show POST error messages, refer to the Troubleshooting tables. NOTE: The following routines are sorted by their test point numbers assigned in the BIOS code. Their actual orders, as executed during POST, can be quite different. Code 02h 03h 04h 06h 08h 09h 0Ah 0Bh 0Ch 0Eh 0Fh 10h 11h 12h 13h 14h 16h 17h 18h 1Ah 1Ch 20h 22h 24h 26h 28h 29h 2Ah 2Ch 2Eh 2Fh 30th 32h 33h 36h 38h 3Ah 3Ch 3Dh 42h 45h 46h 48h 49h 4Ah 4Bh 4Ch 4Eh 50Eh 51h 52h 54h 58h 59h 5Ah 5Bh 5Ch 60h 62h 64h 66h 67h 68h 69h 6Ah 6Bh 6Ch 6Eh 70h 72h 76h 7Ch 7Eh 80h 81h 82h 83h 84h 85h 86h 87h 88h 89h 8Ah 8Bh 8Ch 81h 90h 91h 92h 93h 95h 96h 97h 98h 99h 9Ah 9Ch 9Dh 9Eh 9Fh A0h A2h A4h A8h AAh ACh AEh B0h B2h B4h B5h B6h B9h BAh BBh BCh BDh BEh BFh C0h C1h C2h C3h C4h C5h C6h C7h C8h C9h D2h Beeps 1-2-2-3 1-3-1-1 1-3-1-3 1-3-4-2 1-3-4-3 1-4-1-1 2-1-2-3 2-2-3-1 1-2 1 POST Routine Description Verify Real Mode Disable Non-Maskable Interrupt (NM) Get CPU type Initialize system hardware Initialize chipset with Initial POST values Set IN POST flag Initialize CPU registers Enable CPU cache Initialize caches to initial POST values Initialize I/O component Initialize the local bus IDE Initialize Power Management Load alternate registers with initial POST values Restore CPU control word during warm boost Initialize PCI Bus Mastering devices Initialize keyboard controller BIOS ROM Checksum Initialize cache before memory autosize 8254 timer initialization 8237 DMA controller initialization Reset Programmable Interrupt Controller Test DRAM refresh Test 8742 Keyboard Controller Set ES segment register to 4 GB Enable A20 line Autosize DRAM Initialize POST Memory Manager Clear 512 KB base RAM RAM failure on address line xxxx* RAM failure on data bits xxxx* of low byte of memory bus Enable cache before system BIOS shadow RAM failure on data bits xxxx*of high byte memory bus Test CPU bus-clock frequency Initialize Phoenix Dispatch Manager Warm start shut down Shadow system BIOS ROM Autosize cache Advanced configuration of chipset registers Load alternate registers with CMOS values Initialize interrupt vectors POST device initialization Check ROM copyright notice Check Video configuration against CMOS Initialize PCI bus and devices Initialize all video adapters in system QuietBoot start (optional) Shadow video BIOS ROM Display BIOS copyright notice Display CPU type and speed Initialize EISA board Test keyboard Set key click if enabled Test for unexpected interrupts Initialize POST display service Display prompt "Press F2 to enter SetUP" Disable CPU cache Test RAM between 512 and 640 KB Test extended memory Test extended memory address lines Jump to UserPatchI Configure advanced cache registers Initialize Multi Processor APIC Enable external and CPU cache Setup System Management Mode (SMM) area Display external L2 cache size Load custom defaults (optional) Display shadow-area message Display possible high address for UMB recovery Display error messages Check for configuration errors Check for keyboard errors Set up hardware interrupt vectors Initialize coprocessor if present Disable onboard Super I/O ports and IRQs Late POST device initialization Detect and install external RS232 ports Configure non-MCD IDE controllers Detect and install external parallel ports Initialize PC-compatible PnP ISA devices Reinitialize onboard I/O ports Configure Motherboard Configurable Devices (optional) Initialize BIOS Data Area Enable Non-Maskable Interrupts (NMIs) Initialize Extended BIOS Data Area Test and initialize PS/2 mouse Initialize floppy controller Determine number of ATA drives (optional) Initialize hard disk controllers Initialize local-bus hard disk controllers Jump to UserPatch2 Build MPTABLE for multi-processor boards Install CD ROM for boot Clear huge ES segment register Fixup Multi Processor table Search for option ROMs. One long, two short beeps on checksum failure Check for SMART drive (optional) Shadow option ROMs Set up Power Management Initialize security engine (optional) Enable hardware interrupts Determine number of ATA and SCSI drives Set time of day Check key lock Initialize Typematic rate Erase F2 prompt Scan for F2 key stroke Enter Setup Clear Boot flag Check for errors POST done - prepare to boot operating system One shot beep before boot Terminate QuietBoot (optional) Check password (optional) Prepare Boot Initialize DMI Parameters Initialize PnP Option ROMs Clear parity checkers Display MultiBoot menu Clear screen (optional) check virus and back up reminders Try to boot with INT 19 Initialize POST Error Manager (PEM) Initialize error logging Initialize error display function Initialize system error handler PnPnd dual CMOS (optional) Initialize notebook docking (optional) Initialize notebook docking late Force check (optional) Extended checksum (optional) Unknown interrupts Code E0h E1h E2h E3h E4h E5h E6h E7h E8h E9h EAh EBh ECh EDh EEh EFh F0h F1h F2h F3h F4h F5h F6h F7h Beeps For Boost Block in Flash ROM Initialize the chipset Intitialize the bridge Initialize the CPU Initialize system timer Initializesystem I/O Check force recovery boot Checksum BIOS ROM Go to BIOS Set Huge Segment Initialize Multi Processor Initialize OEM Special code Initialize PIC and DMA Initialize Memory type Initialize Memory size Shadow Boot Block System memory test Initialize interrupts vectors Initialize Run Time Clock Initialize Video Initialize beeper Initialize boot Clear Huge segment Boot to Mini DOS Boot to Full DOS