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Troubleshooting 

Digital DECpc LPv/LPv+

58

MCS Logistics Engineering - Nijmegen

Monitor Troubleshooting

Problem

Possible Cause

Action

Monitor power
indicator is not
on

Monitor is turned off.

Power indicator is defective.

Turn on the monitor.

Replace the failed component.

No screen
display

Configuration error.

Monitor brightness and contrast
controls are incorrectly set.

Run the BIOS SETUP UTILITY to configure the
computer for VGA operation.
Set the jumper for VGA operation.  Refer to

“Main Logic Board Jumpers”

.

Adjust the monitor brightness and contrast
controls.

No monitor
display while
loading
Windows video
drivers

Monitor type incorrectly set.

Set the correct monitor type.  Refer to appropriate
video driver documentation.

Distorted-
rolling-or
flickering
screen display-
or wrong/
uneven color

Monitor incorrectly adjusted.

Monitor signal cable incorrectly
installed.

Adjust accordingly.

Straighten any bent connector pins and then
reconnect.

Color monitor
displaying
monochrome

Computer was turned on before
the monitor was turned on.

Video jumper incorrectly set.

Turn off the computer, turn on the monitor, then
turn the computer back on.

Set the jumper for VGA operation.

Monitor fails to
switch to high-
resolution mode

Appropriate high-resolution
video drivers are not installed or
incorrectly installed.

Correctly install all appropriate high-resolution
video drivers. Refer to the documentation supplied
with the monitor and/or video drivers.

Monitor display
not centered
while loading
Windows video
drivers

Monitor type incorrectly set.

Set the correct monitor type.
Refer to appropriate video driver documentation.

Summary of Contents for DECpc LPv 425sx

Page 1: ...Service Maintenance Manual DECpc LPv LPv PC K MN SD00000 18 JG00 A Copyright Digital Equipment Corporation All rights reserved January 1996 MCS LOGISTICS ENGINEERING NIJMEGEN THE NETHERLANDS...

Page 2: ...lication or disclosure by the U S Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 Copyright...

Page 3: ...e Password 19 Diskette 2 S3 86C805 Windows 3 x Drivers 19 Setting High Resolution Mode for the Monitor Display 20 CONFIGURING THE COMPUTER 21 Running the BIOS Setup Utility 21 Helpful Hints 21 BIOS SE...

Page 4: ...Replacing the Computer Battery Real Time Clock RTC 48 CONNECTING DISKETTE AND IDE DEVICES 49 CONNECTING SCSI DEVICES 49 CHAPTER 4 TROUBLESHOOTING 51 INITIAL TROUBLESHOOTING 51 BEEP CODES 52 Beep Codes...

Page 5: ...a 3 Inch FDD from the Top Bay 38 Figure 3 7 Removing a 3 Inch FDD from the Bottom Bay 38 Figure 3 8 Removing the Mounting Adapter 39 Figure 3 9 Removing the Internal Mounting Tray 40 Figure 3 10 Remo...

Page 6: ...evision History MCS Logistics Engineering Nijmegen 7 Revision History Revision Date Description of Change Revision 1 0 Januari 96 First release of the Service Maintenance Manual describing the DECpc L...

Page 7: ...be serviced since many of the diagnostic tests are designed to test more than one product CAUTION Digital recommends that only A certified engineers attempt to repair this equipment All troubleshooti...

Page 8: ...bit local bus video architecture along with a host of high performance options DECpc LPv LPv computers are the most advanced low profile desktop computers in their class All DECpc LPv LPv computers ar...

Page 9: ...one PC751 WA 1 44MB 170MB 4MB None PC751 WB 1 44MB 240MB 8MB None DECpc LPv 433sx PC752 A9 None PC752 WA 1 44MB 170MB 4MB None PC752 WB 1 44MB 240MB 8MB None DECpc LPv 433dx PC753 A9 None PC753 WA 1 4...

Page 10: ...40MB 8MB None DECpc LPv 433sx FR 742WW A9 None FR 742 WA 1 44MB 170MB 4MB None FR 742 WF 1 44MB 340MB 8MB None DECpc LPv 433dx FR 743WW A9 None FR 743 WA 1 44MB 170MB 4MB None FR 743 WF 1 44MB 340MB 8...

Page 11: ...DOS Video Drivers diskette only when it is necessary to enable the ROM Base Setup option Otherwise use the BIOS Setup utility to change the computer s configuration parameters SMTR EXE Allows to sele...

Page 12: ...he monitor s available resolution and refresh rates 6 If necessary run SMODE EXE to emulate or display a non standard VGA mode 7 Install any applicable DOS or CAD application drivers Additional inform...

Page 13: ...1024x768 72Hz NI 7 Exit the SMTR EXE utility following the instructions on the monitor screen 8 Remove the System and S3 86C805 VGA Utilities and DOS Video Drivers diskette 9 To access SMTR EXE from...

Page 14: ...s and files Follow the procedures on the System and S3 86C805 VGA Utilities and DOS Video Drivers diskette KP EXE KP EXE is an MS DOS executable file that allows to set a password for the keyboard and...

Page 15: ...using the Keyboard Password utility 2 Enter a password then press Enter You are then prompted to type the password again to verify it 3 Enter the password then press Enter The keyboard has been locke...

Page 16: ...86C805 V1 1 1024x768 256 Colors Large Fonts The video setup screen appears again with the S3 driver 7 Press Enter to accept the configuration 8 The MS DOS prompt appears when SETUP completes 9 Type WI...

Page 17: ...gs NOTE Do not use SETUP COM on the System and S3 86C805 VGA Utilities and DOS Video Drivers diskette to make changes to the computer s BIOS Setup utility Use SETUP COM on the System S3 86C805 VGA Uti...

Page 18: ...and 3 or drive types 48 and 49 Once selected you are prompted to execute the auto detect feature by pressing the Enter key Base memory 640 KB Displays the size of base conventional memory Note The mai...

Page 19: ...at 378h 37Ah IRQ7 278h 27Ah IRQ7 3BCh 3BEh IRQ7 Disabled Bi directional mode Compatible mode Enables or disables any desired onboard printer port at the specified address Allows to select between stan...

Page 20: ...the effective CPU speed to be compatible with some speed dependent application programs If an application program does not run correctly at full speed try disabling all caches or changing the CPU spe...

Page 21: ...f video BIOS ROM This DRAM called shadow memory is write protected and has the same addresses as the video BIOS ROM locations When the video BIOS ROM is shadowed the ROM information is copied into an...

Page 22: ...d Keep circuit boards and components away from non conductors Keep clothing away from circuit boards and components Keep circuit boards in anti static bags Be cautious when AC power is exposed when wo...

Page 23: ...Materials Cleaning agent should be an all purpose cleaner that is used in house Required Special Tools None Remedial Diagnostic Test Software QAPLUS fe PC Advanced Diagnostic Software latest version P...

Page 24: ...CO Information BIOS version information Refer to the Digital DECpc Bulletin Board Support for the latest information on BIOS upgrades Network locations North America South America Australia and New Ze...

Page 25: ...ver do the following 1 Turn off power to all external devices connected to computer 2 Turn computer off 3 Unplug power cord from wall outlet 4 Disconnect power cord and monitor cord from computer To r...

Page 26: ...Nijmegen 31 Computer Components Legend Description A Power supply under the internal drive bay B Three ISA expansion slots C Main logic board D 3 inch diskette drive E Front access drive bays F Inter...

Page 27: ...nless you are safely grounded Wear a grounded wrist strap or touch an exposed metal part of the system box chassis A static discharge from your fingers can result in permanent damage to electronic com...

Page 28: ...mpered J3 pins 2 and 3 jumpered J4 pins 2 and 3 jumpered J6 pins 2 and 3 jumpered J7 pins 2 and 3 jumpered Recovery mode Recovery mode Normal operation J14 jumpered J14 open CPU type DX SX J11 pins 1...

Page 29: ...Service Procedures Digital DECpc LPv LPv 34 MCS Logistics Engineering Nijmegen LPv Main Logic Board Jumper Locations Figure 3 3 LPv Main Logic Board Jumper Locations...

Page 30: ...ry modules SIMMs may be added This amount can be increased up to 64 MB However when adding additional memory make sure to Install 36 bit SIMMs having an access time of 70 ns or less Only those configu...

Page 31: ...Service Procedures Digital DECpc LPv LPv 36 MCS Logistics Engineering Nijmegen LPv and LPv SIMM Socket Locations Figure 3 4 LPv and LPv SIMM Socket Locations 0 1 2 3...

Page 32: ...MCS Logistics Engineering Nijmegen 37 Removal Procedures Removing a 5 Inch FDD To remove a 5 Inch FDD 1 Turn off the computer 2 Remove two retaining screws from each side of bottom bay 3 Remove FDD f...

Page 33: ...r power 3 Unlock and remove outside cover 4 Disconnect power and ribbon cables 5 From the top bay remove two retaining screws from each side 6 Remove FDD from bay 7 From the bottom bay remove two reta...

Page 34: ...gen 39 Removing the Mounting Adapter To remove the Mounting Adapter 1 Remove one retaining screw 2 Remove mounting adapter from chassis NOTE Mounting bracket is required when installing a 3 inch devic...

Page 35: ...pc LPv LPv 40 MCS Logistics Engineering Nijmegen Removing the Internal Mounting Tray To remove the Mounting Adapter 1 Loosen four retaining screws 2 Lift mounting tray out of chassis Figure 3 9 Removi...

Page 36: ...istics Engineering Nijmegen 41 Removing the IDE Disk Drive from Mounting Tray To remove the IDE Disk Drive from Mounting Tray 1 Remove four retaining screws 2 Pull drive from mounting tray Figure 3 10...

Page 37: ...in logic board 1 Turn off the computer 2 Disconnect external devices ac power and monitor power 3 Unlock and remove outside cover 4 Remove all connectors 5 Remove expansion boards riser card 6 Remove...

Page 38: ...Power Supply To remove the power supply 1 Disconnect power cord 2 Remove screw securing power on off cable 3 Remove two screws securing power supply to chassis 4 Remove four screws securing power sup...

Page 39: ...the Filler Panels 1 Turn off the computer 2 Disconnect external devices ac power and monitor power 3 Unlock and remove outside cover 4 Carefully place screwdriver through hole provided at side of fron...

Page 40: ...ockets Main Logic Board Cache Tag Sockets 0 to 128 KB E15 through E18 E6 through E8 0 to 256 KB E15 through E18 E12 through E14 E6 through E8 128 to 256 KB E12 through E14 To install a cache SRAM chip...

Page 41: ...Service Procedures Digital DECpc LPv LPv 46 MCS Logistics Engineering Nijmegen Figure 3 14 Installing External Cache Memory...

Page 42: ...neering Nijmegen 47 Installing a Higher Performance CPU To install a higher performance CPU 1 Disconnect power cord 2 Unlock and remove outside cover 3 Remove the CPU 4 Install new CPU 5 Set appropria...

Page 43: ...t see figure Incorrect installation can cause faulty computer operation To replace the computer battery real time clock 1 Record computer configuration settings 2 Turn off the computer 3 Unlock and re...

Page 44: ...If the cable or device is not keyed connect pin 1 of cable to pin 1 of device s socket Pin 1 of the cable is on the edge with colored stripe Pin 1 of the device s socket should be marked with a numbe...

Page 45: ...oting Follow these general procedures to troubleshoot the DECpc LPv LPv computer Press Ctrl Alt Del If the computer fails to boot turn it off wait until all hard disk drives spin down completelyand th...

Page 46: ...ge register write read failure 1 3 1 RAM refresh failure 1 3 3 1st 64 KB RAM chip or data line failure 1 3 4 1st 64 KB RAM odd even logic failure 1 4 1 1st 64 KB RAM address line failure 1 4 2 1st 64...

Page 47: ...2 Screen retrace failure POST and Boot Messages The POST displays messages to alert to errors in hardware softwareand firmware or to provide operating information about the computer Each time the POST...

Page 48: ...se 640 KB base memory 0 KB extended memory Time of day clock stopped Replace RTC Invalid configuration information Run the BIOS Setup utility Diskette drive failure Run the BIOS Setup utility Check al...

Page 49: ...e IDE hard disk drive IDE hard disk drive is not correctly formatted or the requested partition does not exist There is no software on the requested partition IDE hard disk drive jumpers incorrectly s...

Page 50: ...set Hard Disk 1 Hard Disk 2 to Not Installed and IDE Hard Disk Drives options to Disabled This disables the onboard IDE interface NOTE When both IDE and SCSI hard disk drives are installed the compute...

Page 51: ...d Power down the computer and connect the keyboard to the keyboard port Disk Drive Troubleshooting Problem Possible Cause Action IDE SCSI hard disk drive cannot read or write information Incorrect dis...

Page 52: ...r documentation Distorted rolling or flickering screen display or wrong uneven color Monitor incorrectly adjusted Monitor signal cable incorrectly installed Adjust accordingly Straighten any bent conn...

Page 53: ...Setup Check connections Reset controller Replace controller Replace disk Floppy diskette Media Mismatch Drive Not Ready Write Protected Media Unformatted Media Use known good diskette Check size and...

Page 54: ...specific memory location If that location is already allocated a memory conflict results and the expansion board will not operate as expected Note that some memory I O and interrupt locations can be c...

Page 55: ...ler 070 07F Real time clock RTC NMI 080 08F DMA page register 0A0 0A1 Interrupt controller two 0C0 0CF DMA controller two 0F0 Clear math coprocessor busy 0F1 Reset math coprocessor 0F8 0FF Math coproc...

Page 56: ...time clock RTC 4 2 IRQ9 Reserved 5 2 IRQ10 Reserved 6 2 IRQ11 Reserved 7 2 IRQ12 Mouse interrupt 8 2 IRQ13 Math coprocessor 9 2 IRQ14 Hard disk drive 10 2 IRQ15 Reserved 11 1 IRQ3 COM2 COM4 12 1 IRQ4...

Page 57: ...d destructive test Floppy Disk all tests Keyboard all tests COM Ports all tests LPT Ports all tests Pointer Device all tests 3 Successful bootstrap of the on the computer installed Operating System Op...

Page 58: ...Digital DECpc LPv LPv Service Notes MCS Logistics Engineering Nijmegen 67 Appendix A Service Notes This appendix contains the service notes for the DECpc LPv LPv series computer...

Page 59: ...The most current product information and technical support is also available on line The most current device drivers Setup diskettes and technical tips can be found on all of these bulletin boards DEC...

Page 60: ...t to make this document a valuable support to your service efforts for Digital Please fill out the reader feedback form and send or fax it to Digital Equipment Parts Center b v Att MCS Logistics Engin...

Page 61: ...form are used at Digital s direction Did you find errors in this manual If so specify by page What is your general reaction to this manual format completeness organisation etc Is the documentation und...

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