Dell Precision 420 Series Service Manual Download Page 39

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To remove an expansion-card guide cooling fan, perform the following steps.

Remove the computer cover according to the instructions in "

Computer Cover

Rotate the power supply

Remove the

expansion-card guide and fan

Squeeze the tabs on the end of the fan bracket and slide the fan off of the expansion-card guide (

see Figure 24

Control Panel

Figure 25. Control Panel Removal

To remove the control panel, perform the following steps:

Disconnect the control panel cable from the PANEL connector on the system board (see

Figure 28

for the location of the PANEL connector).

Remove the mounting screw that secures the control panel to the hard-disk drive cage door.

Disconnect the chassis intrusion switch cable connector from the control panel.

Disconnect the thermal cable connector from the control panel.

Disconnect the speaker cable connector from the control panel.

Remove the control panel from the chassis.

Chassis Intrusion Switch

Figure 26. Chassis Intrusion Switch Removal

Fan power cable

Fan

Plastic locking tabs (2)

CAUTION: Before you remove the computer cover, see "

Precautionary Measures

Control panel

Thermal cable connector

Control panel cable

Screw

Speaker cable connector

Chassis intrusion switch cable
connector

Chassis intrusion switch

Hard-disk drive cage door

Summary of Contents for Precision 420 Series

Page 1: ...manner whatsoever without the written permission of Dell Computer Corporation is strictly forbidden Trademarks used in this text Dell Dell Precision and the DELL logo are trademarks of Dell Computer Corporation Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and names or their products Dell Computer Corporation disclaims any propriet...

Page 2: ...d Tools Chassis Intrusion Switch Precautionary Measures Drives Restarting the System Power Supply Computer Cover System Board Components Interior Service Label RIMMs Internal View Microprocessor Heat Sink Assembly Front Panel Inserts Cooling Fan Expansion Cards Battery Expansion Card Guide System Board CAUTION FOR YOUR PERSONAL SAFETY AND PROTECTION OF THE EQUIPMENT Before you start to work on the...

Page 3: ...up see Figure 1 4 Raise the back of the cover and pivot it toward the front of the computer 5 Lift the cover off the hooks at the front of the chassis Figure 2 Computer Cover Replacement the power supply to discharge any static charge from your body before touching anything inside the computer While you work periodically touch an unpainted metal surface on the computer chassis to dissipate any sta...

Page 4: ...the chassis It might be helpful to look down into the chassis to verify that the hooks are in place 5 Pivot the cover down toward the back and into position Make sure that the two securing buttons click into place Interior Service Label Figure 3 shows the location of the interior service label on the inside of the top cover This label shows the location of components within the chassis and locatio...

Page 5: ...xpansion card slots Slot 5 is shared with the RAID port function The system contains five 32 bit expansion slots and a 32 bit AGP Pro 50 4X slot If you use an AGP Pro 50 card it occupies the AGP slot and may occupy PCI slots 1 and 2 See Figure 6 for examples of these cards Figure 6 Expansion Cards 1 Externally accessible drive bays 2 Hard disk drive bracket 3 System board 4 Expansion card slots 5 ...

Page 6: ...he card permanently install a metal filler bracket over the empty card slot opening 6 Replace the computer cover and reconnect your computer and peripherals to their power sources and turn them on ALERT Cover was previously removed 7 To reset the chassis intrusion detector enter System Setup select System Security and reset Chassis Intrusion to Enabled or Enabled Silent 1 32 bit PCI expansion card...

Page 7: ...de will swing away from the chassis With the left side of the card guide away from the chassis you can then pull the card guide back and out of the chassis which releases the two right tabs Control Panel Figure 9 Control Panel Removal To remove the control panel perform the following steps NOTE If a setup password has been assigned by someone else contact your network administrator for information...

Page 8: ...rform the following steps 1 From inside the chassis slide the chassis intrusion switch to the side to release it from the chassis 2 Disconnect the chassis intrusion switch cable connector from the control panel see Figure 9 3 Remove the chassis intrusion switch and cable from the chassis Note the routing of the chassis intrusion cable to ensure the replacement is routed in the same manner 4 Instal...

Page 9: ...on cables through the chassis as you disconnect them It is important to route the cables properly when you replace them to prevent them from being pinched or crimped 4 Press down on the retaining tab release button see Figure 12 and pull the drive assembly forward to remove it from the chassis Figure 12 Diskette Drive Removal 5 Remove the screw securing the diskette drive to the bracket see Figure...

Page 10: ...tte LS 120 SuperDisk Tape or CD ROM Drive Removal To remove a diskette LS 120 SuperDisk tape or CD ROM drive perform the following steps 1 Remove the computer cover 2 Disconnect the DC power cable and data cable from the back of the drive 3 Squeeze the metal tabs that extend from each side of the drive bracket toward each other 4 Pull the bracket out of the bay see Figure 14 Figure 14 5 25 Inch Dr...

Page 11: ... the drive 3 Remove the screw holding the drive bracket to the drive bay 4 Rotate the drive bracket upward to disengage it from the latch on the drive bay slide it to the left and lift it out of the chassis see Figure 16 Figure 16 Hard Disk Drive Bracket Removal Hard Disk Drive Removal To remove a hard disk drive from the drive bracket perform the following steps 1 Metal tab 2 Drive bracket 3 Scre...

Page 12: ... 3 Remove the computer cover as instructed in Computer Cover 4 Remove the drive bracket from the chassis as instructed in Hard Disk Drive Bracket Removal 5 Slide the drive into the chosen bay of the bracket oriented so that the connectors on the back of the drive will face the back of the chassis when the bracket is reinstalled see Figure 16 6 Align the four screw holes of the drive and bracket In...

Page 13: ... cover Then reconnect your computer and peripherals to their power sources and turn them on 12 If the drive you just installed is the primary drive insert a bootable diskette into drive A 13 Enter System Setup and update Primary Drive 0 or Primary Drive 1 After you update the System Setup settings reboot the system 14 Partition and logically format your drive before proceeding to the next step See...

Page 14: ...r supply see Figure 20 Figure 20 Rotating the Power Supply 3 Free the power supply by pressing the securing tab labeled RELEASE and rotate it upward to a vertical position See Figure 20 To remove the power supply perform the following steps Figure 21 Removing the Power Supply 1 Remove the computer cover as instructed in Computer Cover 2 Disconnect the AC power cable from the AC power receptacle on...

Page 15: ... Figure 22 shows the system board and the location of all its sockets and connectors Figure 22 System Board Components 1 CD ROM drive audio connector 2 Main power 1 connector desktop chassis 3 Diskette connector 4 Main power 2 connector desktop chassis 5 Battery 6 RIMM memory sockets 7 SCSI narrow connector 8 Secondary EIDE connector 9 Suspend To RAM LED 10 Jumper block see System Board Jumpers 11...

Page 16: ...ff its pin s and carefully fit it down onto the pin s indicated Table 1 System Board Jumper Settings 22 Auxiliary hard disk drive access LED connector 23 PCI expansion slots 24 AGP graphics slot 25 Remote wakeup on LAN connector 26 Primary processor 0 socket 27 Network cable connector 28 Diagnostic LEDs 29 USB connectors 30 Secondary processor 1 socket 31 Line in connector 32 Line out connector 33...

Page 17: ...al speaker connector LINE_IN Audio input connector MIC Microphone connector MONITOR Video connector MOUSE Mouse connector MPWR1 Main power 1 connector desktop MPWR2 Main power 2 connector desktop MTPWR1 Main power 1 connector mini tower MTPWR2 Main power 2 connector mini tower PANEL Control panel connector PARALLEL Parallel port connector sometimes referred to as LPT1 PCIn PCI expansion card conne...

Page 18: ...AUTION Before you remove the computer cover see Precautionary Measures CAUTION To avoid the possibility of electric shock turn off the computer and any peripherals disconnect them from their electrical outlets and then wait at least 5 seconds before you remove the computer cover CAUTION The RIMMs can get extremely hot during system operation To avoid dangerous burns be sure that the RIMMs have had...

Page 19: ...pairs of tabs on the airflow shroud and lift it away b Unscrew and remove the two large thumbscrews that secure the heat sink to the system board c Press outward on the guide bracket release latches d Grasp the processor heat sink assembly firmly and pull it away from the guide bracket assembly assembly see Figure 26 You must use up to 15 pounds of force to disengage the processor from the connect...

Page 20: ...e heat sink to the system board 3 Replace the airflow shroud 1 Airflow shroud 2 Thumbscrews 2 3 Processor heat sink assembly 4 Guide bracket 5 Second processor 1 Airflow shroud 2 Thumbscrews 2 3 Processor heat sink assembly 4 Guide bracket 5 Second processor NOTE Dell recommends that only a technically knowledgeable person perform this procedure CAUTION Before you remove the computer cover see Pre...

Page 21: ...ate the power supply 3 Squeeze in on the two pairs of tabs on the airflow shroud and lift it away 4 Disconnect the fan power cable from the FAN_SYS connector see Figure 22 for location 5 Gently pull on the plastic locking tab and slide the fan toward the power supply to disengage the four latching tabs holding the fan to the back of the chassis see Figure 28 Battery Figure 29 Battery Removal NOTE ...

Page 22: ...y and the socket before attempting to pry out the battery Otherwise you may damage the system board by prying off the socket or by breaking circuit traces on the system board 5 Remove the system battery by carefully prying it out of its socket with your fingers or with a blunt nonconducting object such as a plastic screwdriver When you replace the system battery orient the new battery with the fac...

Page 23: ...rse 2 Push down near each slot to engage the grounding clip onto its corresponding tab 3 Push evenly on both sides of the system board as you slide and lock it into position do not twist the system board 4 Reinstall the mounting screw 5 Reinstall all components on the system board by performing steps 4 through 10 of the removal process in reverse 6 Set the jumpers on the new system board so that t...

Page 24: ...wing caution for your personal safety and to prevent damage to the system from electrostatic discharge ESD Overview Expansion Cards Recommended Tools Expansion Card Guide and Fan Precautionary Measures Control Panel Restarting the System Chassis Intrusion Switch Computer Cover Power Supply Interior Service Label System Board Components Internal View RIMMs Front Panel Microprocessor Heat Sink Assem...

Page 25: ...ront panel see Figure 2 Figure 2 Computer Cover Removal damage to the system board 4 Wear a wrist grounding strap and clip it to an unpainted metal surface such as the padlock loop on the back of the chassis If a wrist grounding strap is not available touch any unpainted metal surface on the back of the computer or on the computer chassis such as the power supply to discharge any static charge fro...

Page 26: ...r the drive cage they will prevent the cover from closing properly 2 Check to see that no tools or extra parts including screws are left inside the computer chassis 3 Face the left side of the computer and hold the cover at a slight angle as shown in Figure 3 4 Align the top of the cover with the top of the chassis and insert the three hooks on the cover into the three recessed slots on the comput...

Page 27: ...ver removed to help you orient yourself when you work inside the computer Figure 5 Orientation View Front Panel To access some drive bays in the mini tower chassis you must first remove the front panel To remove the front panel you first must remove the computer cover see Computer Cover With the cover removed release the panel by pressing the green tab release marked with the icon see Figure 6 Fig...

Page 28: ...the panel toward the chassis until the tabs on the top of the chassis snap into their corresponding slots on the panel Front Panel Inserts Figure 7 Front Panel Insert Removal To remove a 5 25 inch front panel insert perform the following steps 1 Hold the front panel with the front facing you 2 From the front of the front panel use your thumbs to press inward on the insert until it snaps free of th...

Page 29: ... diskette drive up until the drive is clear of the retaining tabs When you replace the 3 5 inch diskette drive on the bracket be sure that the two retaining tabs on the right side of the bracket engage the mounting holes in the side of the 3 5 inch diskette drive bracket Then replace the screw that holds the diskette drive to the bracket To replace the 3 5 inch diskette drive assembly in the chass...

Page 30: ...nd interface cable from the back of the drive 3 Squeeze the metal tabs that extend from each side of the drive bracket toward each other 4 Pull the bracket out of the bay see Figure 11 5 Turn the drive bracket assembly upside down and unscrew the four screws that secure the drive to the bracket see Figure 12 Figure 11 5 25 Inch Drive Removal Figure 12 5 25 Inch Drive Bracket 1 3 5 inch diskette dr...

Page 31: ...ve the front panel if it is not already off 5 Attach the new drive to the drive bracket Turn the drive upside down and locate the four screw holes around its perimeter Fit the bracket over the drive and then tilt the front of the drive up so that the bracket drops down into place To ensure proper installation all screw holes should be aligned and the tabs on the front of the bracket should be flus...

Page 32: ...TE on the system board Check all cable connections Fold cables out of the way to provide airflow for the fan and cooling vents 10 If the 5 25 inch drive bay was previously empty remove the front panel insert from the front panel 11 Replace the front panel 12 Replace the computer cover reconnect your computer and peripherals to their power sources and turn them on 13 If the replacement drive was no...

Page 33: ...eviously occupied by the drive you removed oriented so that the connectors on the back of the drive will face the back of the chassis with the power connector located above the data interface connector see Figure 16 5 Align the four screw holes of the drive and bracket Insert and tighten the screws see Figure 16 Figure 16 Inserting a Hard Disk Drive in the Bracket NOTE Tape drives sold by Dell com...

Page 34: ...irmly seated 8 Connect one of the device connectors on the EIDE cable to the 40 pin interface connector on the back of the hard disk drive NOTICE You must match the colored strip on the EIDE cable with pin 1 on the drive s interface connector to avoid possible damage to your system Figure 18 Attaching Hard Disk Drive Cables 1 Drive bracket 2 Drive 3 Screws 4 1 Chassis drive cage 2 Drive bracket 3 ...

Page 35: ...ee the documentation for your operating system for instructions 14 Test the hard disk drive by running the Dell Diagnostics see the online System User s Guide for more information 15 If the drive you just installed is the primary drive install your operating system on the hard disk drive Refer to the documentation that came with your operating system AGP Card Brace To access any expansion cards an...

Page 36: ...s provide five 32 bit Peripheral Component Interconnect PCI expansion card slots Slot 5 is shared with the RAID port function The system contains five 32 bit expansion slots and a 32 bit AGP Pro 110 4X slot If you use an AGP Pro 50 or Pro110 card it occupies the AGP slot and may occupy PCI slots 1 and 2 See Figure 20 for examples of these cards Industry standard architecture ISA expansion cads are...

Page 37: ... bracket over the empty card slot opening Expansion Card Installation To install a replacement expansion card perform the following steps 1 Remove the computer cover 2 Rotate the power supply away from the system board 3 Prepare the card as necessary using the instructions provided with the card 4 Insert the expansion card into the expansion card connector 5 If the expansion card is full length in...

Page 38: ...system board 2 Remove the AGP card brace 3 Remove all full length expansion cards 4 Press down on the top of the card guide to release the tab from its slot located on the lower left area on the front of the chassis see Figure 23 5 Rotate the top of the card guide away from the chassis front 6 Disconnect the fan power cable from its connector on the system board 7 Lift the expansion card guide and...

Page 39: ... the PANEL connector 2 Remove the mounting screw that secures the control panel to the hard disk drive cage door 3 Disconnect the chassis intrusion switch cable connector from the control panel 4 Disconnect the thermal cable connector from the control panel 5 Disconnect the speaker cable connector from the control panel 6 Remove the control panel from the chassis Chassis Intrusion Switch Figure 26...

Page 40: ...t Chassis Intrusion to Enabled or Enabled Silent see your User s Guide for instructions Power Supply To access some components on the system board you may have to rotate the system power supply out of the way Use this procedure to rotate the supply out of the chassis or to completely remove it To rotate or remove the power supply perform the following steps 1 Remove the computer cover 2 Lay the co...

Page 41: ...o the drives and to the system board e Using a flat tipped screwdriver pry out the power supply hinge pin from the chassis foot f While supporting the weight of the power supply pull the power supply hinge pin completely out to release the power supply from the chassis When installing a replacement power supply remember to rotate and secure the L end of the hinge pin into the groove on the chassis...

Page 42: ...tandby power LED 15 Control panel connector 16 MT power 2 connector mini tower chassis 17 MT power 1 connector mini tower chassis 18 Modem TAPI connector 19 Card cage fan power connector 20 Auxiliary sound input connector 21 PCI RAID expansion card connector 22 Auxiliary hard disk drive access LED connector 23 PCI expansion slots 24 AGP graphics slot 25 Remote wakeup on LAN connector 26 Primary pr...

Page 43: ...ated Table 1 System Board Jumper Settings System Board Labels Table 2 lists the labels for connectors and sockets on your system board and it gives a brief description of their functions Table 2 System Board Connector and Socket Labels 33 Microphone connector 34 Mouse keyboard stacked 35 System fan power connector 36 Serial port 1 serial port 2 stacked 37 Parallel port external SCSI port stacked J...

Page 44: ...y microprocessor connector STANDBY Standby power LED STR_LED Suspend to RAM LED USB USB connectors TAPI Telephony connector WOL Remote Wakeup on LAN power connector CAUTION Before you remove the computer cover see Precautionary Measures CAUTION To avoid the possibility of electric shock turn off the computer and any peripherals disconnect them from their electrical outlets and then wait at least 5...

Page 45: ...computer cover rotate the power supply and check the installed RIMMs to make sure that they are seated properly in their sockets Then repeat steps 3 4 and 5 7 Reset the chassis intrusion detector by changing Chassis Intrusion to Enabled or Enabled Silent 8 When the System Memory total is correct press Esc to exit System Setup 9 Run the Dell Diagnostics to verify that the RIMMs are operating proper...

Page 46: ...f force to disengage the processor from the connector Figure 32 Microprocessor Removal Figure 33 Microprocessor Replacement 4 Insert the new microprocessor into the system board connector see Figure 33 NOTE Before disconnecting a peripheral from the system or removing a component from the system board verify that the standby power LED on the system board has turned off For the location of this LED...

Page 47: ...ocessor cooling fan perform the following steps 1 Remove the computer cover according to the instructions in Computer Cover 2 Rotate the power supply 3 Remove the airflow shroud by squeezing in on the two pairs of tabs on the shroud and lift it away 4 Remove the fan power cable from its connector see Figure 28 for the location of the system FAN connector 5 Gently pull the plastic locking tab and p...

Page 48: ...ettings 2 To access the battery on the system board rotate the power supply as described in Rotating the Power Supply 3 If installed remove the CD ROM drive according to the instructions in Diskette LS 120 SuperDisk Tape or CD ROM Drive Removal to access the battery 4 Locate the battery and remove it The battery is mounted in a socket labeled BATTERY at the upper front right corner of the system b...

Page 49: ... board in the chassis by performing steps 11 through 13 of the removal process in reverse 2 Push down near each slot to engage the grounding clip onto its corresponding tab 3 Push evenly on both sides of the system board as you slide and lock it into position do not twist the system board 4 Reinstall the mounting screw 5 Reinstall all components on the system board by performing steps 4 through 10...

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