Acer Aspire 4720z Service Guide
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Chapter 475 Error Message List No beep Error MessagesFRU/Action in Sequence No beep, power-on indicator turns off and LCD is blank.Power source (battery pack and power adapter). See “Power System Check” on page 69.. Ensure every connector is connected tightly and correctly. Reconnect the DIMM. LED board. System board. No beep, power-on indicator turns on and LCD is blank.Power source (battery pack and power adapter). See “Power System Check” on page 69.. Reconnect the LCD connector Hard disk drive LCD inverter ID LCD cable LCD Inverter LCD System board No beep, power-on indicator turns on and LCD is blank. But you can see POST on an external CRT. Reconnect the LCD connectors. LCD inverter ID LCD cable LCD inverter LCD System board No beep, power-on indicator turns on and a blinking cursor shown on LCD during POST.Ensure every connector is connected tightly and correctly. System board No beep during POST but system runs correctly. Speaker System board
76Chapter 4 Phoenix BIOS Beep Codes CodeBeepsPOST Routine Description 02h Verify Real Mode 03h Disable Non-Maskable Interrupt (NMI) 04h Get CPU type 06h Initialize system hardware 08h Initialize chipset with initial POST values 09h Set IN POST flag 0Ah Initialize CPU registers 0Bh Enable CPU cache 0Ch Initialize caches to initial POST values 0Eh Initialize I/O component 0Fh Initialize the local bus IDE 10h Initialize Power Management 11h Load alternate registers with initial POST values 12h Restore CPU control word during warm boot 13h Initialize PCI Bus Mastering devices 14h Initialize keyboard controller 16h 1-2-2-3 BIOS ROM checksum 17h Initialize cache before memory autosize 18h 8254 timer initialization 1Ah 8237 DMA controller initialization 1Ch Reset Programmable Interrupt Controller 20h 1-3-1-1 Test DRAM refresh 22h 1-3-1-3 Test 8742 Keyboard Controller 24h Set ES segment register to 4 GB 26h Enable A20 line 28h Autosize DRAM 29h Initialize POST Memory Manager 2Ah Clear 215 KB base RAM 2Ch 1-3-4-1 RAM failure on address line xxxx 2Eh 1-3-4-3 RAM failure on data bits xxxx of low byte of memory bus 2Fh Enable cache before system BIOS shadow 30h 1-4-1-1 RAM failure on data bits xxxx of high byte of memory bus 32h Test CPU bus-clock frequency 33h Initialize Phoenix Dispatch Manager 36h Warm start shut down 38h Shadow system BIOS ROM 3Ah Autosize cache 3Ch Advanced configuration of chipset registers 3Dh Load alternate registers with CMOS values 42h Initialize interrupt vectors 45h POST device initialization
Chapter 477 46h 2-1-2-3 Check ROM copyright notice 48h Check video configuration against CMOS 49h Initialize PCI bus and devices 4Ah Initialize all video adapters in system 4Bh QuietBoot start (optional) 4Ch Shadow video BIOS ROM 4Eh Display BIOS copyright notice 50h Display CPU type and speed 51h Initialize EISA board 52h Test keyboard 54h Set key click if enabled 58h 2-2-3-1 Test for unexpected interrupts 59h Initialize POST display service 5Ah Display prompt “Press F2 to enter SETUP” 5Bh Disable CPU cache 5Ch Test RAM between 512 and 640 KB 60h Test extended memory 62h Test extended memory address lines 64h Jump to User Patch1 66h Configure advanced cache registers 67h Initialize Multi Processor APIC 68h Enable external and CPU caches 69h Setup System Management Mode (SMM) area 6Ah Display external L2 cache size 6Bh Load custom defaults (optional) 6Ch Display shadow-area message 6Eh Display possible high address for UMB recovery 70h Display error messages 72h Check for configuration errors 76h Check for keyboard errors 7Ch Set up hardware interrupt vectors 7Eh Initialize coprocessor if present 80h Disable onboard Super I/O ports and IRQs 81h Late POST device initialization 82h Detect and install external RS232 ports 83h Configure non-MCD IDE controllers 84h Detect and install external parallel ports 85h Initialize PC-compatible PnP ISA devices 86h Re-initialize onboard I/O ports 87h Configure Motherboard Configurable Devices (optional) 88h Initialize BIOS Area 89h Enable Non-Maskable Interrupts (NMIs) 8Ah Initialize Extended BIOS Data Area 8Bh Test and initialize PS/2 mouse CodeBeepsPOST Routine Description
78Chapter 4 8Ch Initialize floppy controller 8Fh Determine number of ATA drives (optional) 90h Initialize hard-disk controllers 91h Initialize local-bus hard-disk controllers 92h Jump to UserPatch2 93h Build MPTABLE for multi-processor boards 95h Install CD ROM for boot 96h Clear huge ES segment register 97h Fixup Multi Processor table 98h 1-2 Search for option ROMs. One long, two short beeps on checksum failure. 99h Check for SMART drive (optional) 9Ah Shadow option ROMs 9Ch Set up Power Management 9Dh Initialize security engine (optional) 9Eh Enable hardware interrupts 9Fh Determine number of ATA and SCSI drives A0h Set time of day A2h Check key lock A4h Initialize Typematic rate A8h Erase F2 prompt AAh Scan for F2 key stroke ACh Enter SETUP AEh Clear Boot flag B0h Check for errors B2h POST done- prepare to boot operating system B4h 1 One short beep before boot B5h Terminate QuietBoot (optional) B6h Check password (optional) B9h Prepare Boot BAh Initialize DMI parameters BBh Initialize PnP Option ROMs BCh Clear parity checkers BDh Display MultiBoot menu BEh Clear screen (optional) BFh Check virus and backup reminders C0h Try to boot with INT 19 C1h Initialize POST Error Manager (PEM) C2h Initialize error logging C3h Initialize error display function C4h Initialize system error handler C5h PnPnd dual CMOS (optional) C6h Initialize notebook docking (optional) C7h Initialize notebook docking late C8h Force check (optional) C9h Extended checksum (optional) CodeBeepsPOST Routine Description
Chapter 479 D2h Unknown interrupt CodeBeeps E0h Initialize the chipset E1h Initialize the bridge E2h Initialize the CPU E3h Initialize the system timer E4h Initialize system I/O E5h Check force recovery boot E6h Checksum BIOS ROM E7h Go to BIOS E8h Set Huge Segment E9h Initialize Multi Processor EAh Initialize OEM special code EBh Initialize PIC and DMA ECh Initialize Memory type EDh Initialize Memory size EEh Shadow Boot Block EFh System memory test F0h Initialize interrupt vectors F1h Initialize Run Time Clock F2h Initialize video F3h Initialize System Management Mode F4h 1 Output one beep before boot F5h Boot to Mini DOS F6h Clear Huge Segment F7h Boot to Full DOS CodeBeepsPOST Routine Description
80Chapter 4 Index of Sym ptom-to-FRU Error Message LCD-Related Symptoms Symptom / ErrorAction in Sequence LCD backlight doesnt work LCD is too dark LCD brightness cannot be adjusted LCD contrast cannot be adjustedEnter BIOS Utility to execute “Load Setup Default Settings”, then reboot system. Reconnect the LCD connectors. Keyboard (if contrast and brightness function key doesnt work). LCD inverter ID LCD cable LCD inverter LCD System board Unreadable LCD screen Missing pels in characters Abnormal screen Wrong color displayedReconnect the LCD connector LCD inverter ID LCD cable LCD inverter LCD System board LCD has extra horizontal or vertical lines displayed.LCD inverter ID LCD inverter LCD cable LCD System board Indicator-Related Symptoms Symptom / ErrorAction in Sequence Indicator incorrectly remains off or on, but system runs correctlyReconnect the inverter board Inverter board System board Power-Related Symptoms Symptom / ErrorAction in Sequence Power shuts down during operation Power source (battery pack and power adapter). See “Power System Check” on page 69. Battery pack Power adapter Hard drive & battery connection board System board The system doesn’t power-on. Power source (battery pack and power adapter). See “Power System Check” on page 69. Battery pack Power adapter Hard drive & battery connection board System board The system doesn’t power-off. Power source (battery pack and power adapter). See “Power System Check” on page 69. Hold and press the power switch for more than 4 seconds. System board
Chapter 481 Battery can’t be charged See “Check the Battery Pack” on page 71. Battery pack System board PCMCIA-Related Symptoms Symptom / ErrorAction in Sequence System cannot detect the PC Card (PCMCIA) PCMCIA slot assembly System board PCMCIA slot pin is damaged. PCMCIA slot assembly Memory-Related Symptoms Symptom / ErrorAction in Sequence Memory count (size) appears different from actual size.Enter BIOS Setup Utility to execute “Load Default Settings, then reboot system. DIMM System board Speaker-Related Symptoms Symptom / ErrorAction in Sequence In Windows, multimedia programs, no sound comes from the computer. Audio driver Speaker System board Internal speakers make noise or emit no sound. Speaker System board Power Management-Related Symptoms Symptom / ErrorAction in Sequence The system will not enter hibernation See “Save to Disk (S4)” on page 38. Keyboard (if control is from the keyboard) Hard disk drive System board The system doesnt enter hibernation mode and four short beeps every minute.Press Fn+ oand see if the computer enters hibernation mode. Touchpad Keyboard Hard disk connection board Hard disk drive System board The system doesn’t enter standby mode after closing the LCDSee “Save to Disk (S4)” on page 38. LCD cover switch System board The system doesnt resume from hibernation mode.See “Save to Disk (S4)” on page 38. Hard disk connection board Hard disk drive System board The system doesnt resume from standby mode after opening the LCD.See “Save to Disk (S4)” on page 38. LCD cover switch System board Power-Related Symptoms Symptom / ErrorAction in Sequence
82Chapter 4 NOTE: If you cannot find a symptom or an error in this list and the problem remains, see “Undetermined Problems” on page 84. Battery fuel gauge in Windows doesn’t go higher than 90%. Remove battery pack and let it cool for 2 hours. Refresh battery (continue use battery until power off, then charge battery). Battery pack System board System hangs intermittently. Reconnect hard disk/CD-ROM drives. Hard disk connection board System board Peripheral-Related Symptoms Symptom / ErrorAction in Sequence System configuration does not match the installed devices. Enter BIOS Setup Utility to execute “Load Default Settings”, then reboot system. Reconnect hard disk/CD-ROM/diskette drives. External display does not work correctly. Press Fn+F5, LCD/CRT/Both display switching System board USB does not work correctly System board Print problems. Ensure the “Parallel Port” in the “Onboard Devices Configuration” of BIOS Setup Utility is set to Enabled. Onboard Devices Configuration Run printer self-test. Printer driver Printer cable Printer System Board Serial or parallel port device problems. Ensure the “Serial Port” in the Devices Configuration” of BIOS Setup Utility is set to Enabled. Device driver Device cable Device System board Keyboard/Touchpad-Related Symptoms Symptom / ErrorAction in Sequence Keyboard (one or more keys) does not work. Reconnect the keyboard cable. Keyboard System board Touchpad does not work. Reconnect touchpad cable. Touchpad board System board Modem-Related Symptoms Symptom / ErrorAction in Sequence Internal modem does not work correctly. Modem phone port modem combo board System board Power Management-Related Symptoms Symptom / ErrorAction in Sequence
Chapter 483 Intermittent Problems Intermittent system hang problems can be caused by a variety of reasons that have nothing to do with a hardware defect, such as: cosmic radiation, electrostatic discharge, or software errors. FRU replacement should be considered only when a recurring problem exists. When analyzing an intermittent problem, do the following: 1.Run the advanced diagnostic test for the system board in loop mode at least 10 times. 2.If no error is detected, do not replace any FRU. 3.If any error is detected, replace the FRU. Rerun the test to verify that there are no more errors.
84Chapter 4 Undetermined Problems The diagnostic problems does not identify which adapter or device failed, which installed devices are incorrect, whether a short circuit is suspected, or whether the system is inoperative. Follow these procedures to isolate the failing FRU (do not isolate non-defective FRU). NOTE: Verify that all attached devices are supported by the computer. NOTE: Verify that the power supply being used at the time of the failure is operating correctly. (See “Power System Check” on page 69.): 1.Power-off the computer. 2.Visually check them for damage. If any problems are found, replace the FRU. 3.Remove or disconnect all of the following devices: TNon-Acer devices TPrinter, mouse, and other external devices TBattery pack THard disk drive TDIMM TCD-ROM/Diskette drive Module TPC Cards 4.Power-on the computer. 5.Determine if the problem has changed. 6.If the problem does not recur, reconnect the removed devices one at a time until you find the failing FRU. 7.If the problem remains, replace the following FRU one at a time. Do not replace a non-defective FRU: TSystem board TLCD assembly