HP 14XL352, 14XL250, 14XL355, 14XL246 Backlight brightness cannot be adjusted with Fn+F7 or Fn+F8

Page 65

Presario 1400 Series

Models: XL240, XL241, XL242, XL244, XL245, XL246, XL247, XL250, XL340, XL341, XL342, XL343, XL344, XL345, XL346, XL350, XL352, XL355, and XL356

Solving Display Problems

Problem

The light tubes on the edge of the display panel do not light up, and the Power-On Self-Test (POST) completes when the unit is powered up.**

The light tubes on the edge of the display panel do not light up, and the Power-On Self- Test (POST) does not complete when the unit is powered up.**

Backlight (brightness) cannot be adjusted with Fn+F7 or Fn+F8.

Probable Cause

Improper backlight or display cable connections

Defective inverter board

Defective display cable

Defective display panel

Defective system board

Defective system board

Improper display cable connections

Defective inverter board

Defective display cable

Defective system board

Solution

Replace the display assembly.

Replace the display assembly.

Replace the display assembly.

Replace the display assembly.

Replace the system board.

Replace the system board.

1.Reseat the display cable to the system board.

2.Replace the display assembly.

Replace the display assembly.

Replace the display assembly.

Replace the system board.

**This problem indicates that the backlight or its power circuitry has failed. Since you cannot observe the POST results on the display panel when the backlight is not functioning, connect the unit to an external monitor before powering it up. If an external monitor is not available, confirm that POST completes by opening and closing the display, listening for the single or double beep and watching for the icons to turn on at the front of the Notebook.

Continued

PRESARIO NOTEBOOK MAINTENANCE AND SERVICE GUIDE 1400 SERIES

TROUBLESHOOTING 25

Image 65

Contents Welcome to the Maintenance & Service Guide MSG Using this Guide Before You Begin Preface Locating Additional Information XL240 XL241 XL242 Display BatteryProcessor Hard Drive CD or DVD DriveXL247-250 TV-Out XL343 XL344 XL345 Display XL340 XL341 XL342 DisplayTV-Out XL355 XL356 Display XL346 XL350 XL352 DisplayDescription Front of UnitInternet Zone Buttons and Lights No. Description Front Bezel ComponentsRight Side Components Left Side Components Underneath the Unit Rear Connectors Weight DimensionsStand-Alone Battery Pack Li-Ion Pack AC Power Requirements InputAltitude Relative Humidity non-condensingShock VibrationSystem Interrupts Hardware IRQ System Function System InterruptsSystem DMA System I/O Addresses System Function Shipping ConfigurationHardware DMA System Function Address HexPresario 1400 Series Memory Address System Function System Memory Catalog13-in HPA Display 12.1-in 13.0-in Active Area Display DimensionsContrast Ratio BrightnessDth 13.3-in TFT Display 12.1-in DimensionsWiCylinders High/Low Number of Read/Write Heads Memory ExpansionSystem Memory Expansion Board Memory Total Memory Hard Drive Drive Type 12.0 GB 18.0 GB Capacity Per Drive Logical ConfigurationSeek Times Transfer Rate AtSpin Up Time Data Buffer Capacity CD/DVD Drive 24x CD-ROM Dimensions Weight Rotational Speed Typical Transfer RateAccess Time Energy Temperature RequirementsOperating Lifetime Universal Serial Bus Pin AssignmentsExternal Monitor External MonitorRJ-45 NIC RJ-45 NICAC Adapter VideoBattery and Power Management Full Off Indicators Standby Mode Hibernation Mode Off ModeAutomatic ActivationHome/Office Desk Power Scheme AC Power Battery Power Always OnPortable/Laptop Default Alarm Settings Low Battery Critical Battery AlarmsIncreasing Battery Pack Operating Time Maximizing the Energy Stored Battery Charge Time Li-ion Battery Pack Battery PowerDisposing of a Used Battery Pack Troubleshooting Run the Computer Checkup Test Preliminary StepsClearing the Power-On Password Power-On Self-Test Messages 102-System Board Failure Power-On Self-Test PostSystem Options Not Set Recommended ActionXX000YZZ 201-Memory Error Probable Cause Run Computer Checkup Test View System Information Inspect Compaq DiagnosticsComputer Checkup Test ROM View System Information InspectDiagnostic Error Codes Error Code Memory, Keyboard, and Parallel Printer Test Error CodesDescription Recommended Action Diskette Drive and Serial Test Error CodesHard Drive Test Error Codes Video Test Error Codes Video Test Error Codes 2458-xx 2468-xx 2477-xx 2478-xx 2480-xx DVD or CD Drive Test Error Codes TouchPad/Pointing Device Interface Test Error CodesTroubleshooting without Diagnostics Before Replacing Parts Problem Solving Audio Problems Probable Cause Solution Solving Minor ProblemsSolving Battery Pack/Gauge Problems Presario 1400 Series Solving DVD or CD Drive Problems Solving Battery Pack/Gauge Problems Probable Cause SolutionSolving Diskette Drive Problems Solving Diskette Drive ProblemsSolving Display Problems Solving Display ProblemsBacklight brightness cannot be adjusted with Fn+F7 or Fn+F8 Solving Display Problems Probable Cause Solution Solving Hard Drive Problems Solving Hard Drive ProblemsSolving Hardware Installation Problems Solving Hardware Installation ProblemsSolving Keyboard/Numeric Keypad Problems Solving Keyboard and Numeric Keypad ProblemsProblem Solving Memory Problems Probable Cause Solution Solving Memory ProblemsProblem Solving PC Card ProblemsSolving Power Problems Probable Cause Solving Power ProblemsSolving Printer Problems Solving Printer ProblemsSolving TouchPad/Pointing Device Problems Solving TouchPad/Pointing Device ProblemsSerial Number Removal SequenceGenerating Static Electrostatic DischargeScrews Service ConsiderationsTool and Software Requirements Presario 1400 Series Battery Pack Presario 1400 Series Cosmetic Side Covers Speaker Port Covers Modem/Memory Access Door Modem or Network/Modem Combo Card Extended Memory Card DVD, CD-Rom, or CD-RW Drive Presario 1400 Series Hard Drive Presario 1400 Series Service Removable Parts Electrostatic Discharge Service Considerations Cable Illustrations Cables and ConnectorsCables ZIF Connectors Connectors and Plastic PartsSpeaker Assembly Cable Keyboard Ribbon Cable Internet Button Board Cover Presario 1400 Series Keyboard PCA Button Board Presario 1400 Series Display Panel Assembly MP3 Zone Cover Heatspreader with Fan Assembly Fan Assembly Palmrest Cover with TouchPad Upper CPU Presario 1400 Series Modem/Modem-NIC Combo Cable Presario 1400 Series MP3 Audio Board Presario 1400 Series Speaker Assembly Presario 1400 Series System Board Presario 1400 Series Presario 1400 Series Processor Presario 1400 Series Replacing the Processor Parts Catalog System Unit Boards Display Assembly Spare Part Items No. Description Mass Storage DevicesSpare Part Items Description Miscellaneous Hardware Kit Miscellaneous Hardware KitSpare Part Items Description Miscellaneous PartsBuild-to-Order Models Build-to-Order ModelsPart Applicable Models Availability Number Alphabetical Spares ListingSpare Part Description Part Number Part Applicable Models Number 218497-001

Related manuals

Manual 8 pages 26.72 Kb

Manual 14 pages 60.01 Kb