Packard Bell oneTwo M3350 Service Manual

Contents

Packard Bell oneTwo M3350 Service Manual Manual pdf 70 page image

62 Packard Bell oneTwo M3350 / oneTwo M3351 / oneTwo L5350 / oneTwo L5351 Service GuideSystem Internal Inspection1. Turn off the power to the computer and all peripherals.2. Unplug the power cord from the computer.3. Unplug the network cable and all connected peripheral devices from the computer.4. Place the computer on a flat, steady surface.5. Remove the side panel as described in page 20.6. Verify that the processor, memory module(s), and expansion board(s) are properly seated.7. Verify that all power and data cables are firmly and properly attached to the installed drives.8. Verify that all cable connections inside the system are firmly and properly attached to their appropriatemainboard connectors.9. Verify that all components are Acer-qualified and supported.10. Reinstall the side panel.11. Power on the system.If the cause of the failure is still can not be determined, review the POST messages and BIOScheckpoints during the system startup.CheckpointsA checkpoint is either a byte or word value output to I/O port 80h. The BIOS outputs checkpoints duringbootblock and Power-On Self Test (POST) to indicate the task the system is currently executing. Checkpointsare very useful in aiding software developers or technicians in debugging problems that occur during thepre-boot process.Viewing BIOS CheckpointsViewing all checkpoints generated by the BIOS requires a checkpoint card, also referred to as a POST card orPOST diagnostic card. These are ISA or PCI add-in cards that show the value of I/O port 80h on a LEDdisplay. Checkpoints may appear on the bottom right corner of the screen during POST. This display method islimited, since it only displays checkpoints that occur after the video card has been activated.Boot Block Initialization Code CheckpointsThe boot block initialization code sets up the chipset, memory, and other components before system memoryis available. The following table describes the type of checkpoints that may occur during the boot blockinitialization portion of the BIOS.NOTE Please note that checkpoints may differ between different platforms based on systemconfiguration. Checkpoints may change due to vendor requirements, system chipset or optionROMs from add-in PCI devices.Checkpoint DescriptionBefore D1 Early chipset initialization is done. Early super I/O initialization is done including RTC andkeyboard controller. NMI is disabled.D1 Perform keyboard controller BAT test. Check if waking up from power managementsuspend state. Save power-on CPUID value in scratch CMOS.D0 Go to flat mode with 4GB limit and GA20 enabled. Verify the bootblock checksum.D2 Disable CACHE before memory detection. Execute full memory sizing module. Verify thatflat mode is enabled.D3 If memory sizing module not executed, start memory refresh and do memory sizing inbootblock code. Do additional chipset initialization. Re-enable CACHE. Verify that flatmode is enabled.D4 Test base 512 KB memory. Adjust policies and cache first 8 MB. Set stack.