Page 1: ...HP 82718A Expansion Pod Service Manual WKSl HEWLETT WmM PACKARD ...
Page 2: ...m HEWLETT PACKARD HP 82718A Expansion Pod Service Manual Reorder Number Printed In U S A 82718 90006 84 ...
Page 3: ...emoval and Replacement 4 1 Introduction 4 1 4 2 Required Tools 4 1 4 3 Disassembly Procedure 4 1 4 4 To remove the power PCA 4 2 4 5 To remove the modem PCA 4 4 4 6 To remove the ROM connector 4 4 4 7 Reassembly Procedure 4 4 4 8 To reassemble the ROM connector 4 5 4 9 Td reassemble the power PCA 4 6 5 Troubleshooting and Diagnostics 5 1 Introduction 5 1 5 2 Required Tools 5 2 5 3 Initial Preparat...
Page 4: ... Test Setup 4 5 4 8 Installing the ROM connector Shield Screws 4 6 4 9 I O Panel Installation 4 3 4 10 Installingthe PCAs 4 7 4 11 Securing the ROM Connector Shield 4 7 6 HP 82718A Expansion PodExploded View 0 3 6 2 Component Location Diagram 3 5 7 1 Power PCA Electronic Disc Schematic 7 3 2 Power PCA Modem Interface Schematic 7 5 7 3 Power PCA Power Supply Schematic 7 7 Tables Table Title Page 1 ...
Page 5: ...on 3 Functional Description This section gives a brief description ofthe functions ofthe major blocks in the pod Section 4 Removal and Replacement This section tells how to remove and replace podassemblies Section 5 Troubleshooting andDiagnostics Thissection tellshow to troubleshoot andrepair the pod Section 6 Replaceable Parts This section lists the replaceable parts and contains an exploded view...
Page 6: ...disconnect on call failure or loss of communications Automatic dialer pulse tone The modem is controlled by its own MPU microprocessing unit and associated circuitry Low level modem commands are included in 4K bytes of ROM Up to64K bytes ofextended electronic disc memory can be installed inthepod inincrements of8K bytes Standard configurations are 24K 32K and 64K hytes High level modem and electro...
Page 7: ...ntal Operating temperature 0 to 45 C 32 to 113 F Storage temperature 40 to f 55 C 40 to 131 F Recharging temperature 1 10 to 40 C 50 to 104 F HP 82718A 1 4 Identification The serial number of the HP 82718A is used for identification and the determination of warranty status It is located on the bottom overlay Its format is described below Y Y W W n K A B Q S X X X X X Sequence number Location manuf...
Page 8: ...nd how to verify its func tional operation 2 2 Preparation To prepare your pod for operation do the following a If the end retainers are in place remove them by unscrewing the six long screws in the bottom case Figure 2 1 End Retainer Screws b Be sure the HP 75 is turned off c Remove the battery pack from the HP 75 ...
Page 9: ...5 on the top case and installing the end retainers ROM Connector Figure 2 2 HP 75 Installation e Install charged batteries and the battery door in the pod Figure 2 3 Batteries Installed in the Pod f Remove a dummy ROM if present from either of the other two ports in the HP 75 and install a pod diagnostic ROM ...
Page 10: ...o into the edit mode press rEPirl type in RUN P and press fWrNl The pod testprogram runs You will need to press IEDIT Itwice if this is a cold start c Ifthe unit is good various messages are displayed and then pod OK nn is displayed where nn corresponds tothe number ofKbytes ofinstalled RAM asindicated on the pod label Incase anerror message is displayed refer to section 5 for analysis of the resu...
Page 11: ...gure 3 1 HP 82718A Block Diagram 3 2 The Memory Management IC MEMIC 1LH7 Memory Manager 1LH7 U17 provides the general interface between the HP 75 bus and the external memory and modem controller in the pod The input to U17 comes from the HP 75 8 bit time multiplexed address data bus Output to the HP 75 is placed on the HP 75 bus by U17 Six control lines are used to indicate the type of information...
Page 12: ...tronic disc memory at address 05F020H Modem data is at address 05F000H It also provides a signal to the power supply to turn on the modem power when it is required A global disable signal INIT U28 41 can be tied high to isolate U28 from the bus for troubleshooting U15 is a Schmitt trigger that provides proper timing signals for the STANDBY RESET and STABLE lines in U2 and U28 3 5 Power Supply The ...
Page 13: ... to flow in Q3 R18 increases the voltage on the base of Q3 when the modem is turned on to provide for the additional energy required by the modem Pod battery number one is located electrically in the HP 75 battery circuit and pod battery number two is effectively connected in parallel with it Therefore it is possible for the HP 75 battery detect circuit to detect the level of the pod batteries The...
Page 14: ...r test HP 75 8720 0001 Nutdriver 3 16 inch 8710 0555 Pliers needlenose right angle 5061 7248 ROM diagnostic 8710 0899 Screwdriver Pozidriv 1 4 3 Disassembly Procedure The following procedure describes the steps you should take to disassemble the pod CAUTION Always remove the batteries before disassembling the pod Otherwise damage to components may result Make sure your work station is protected ag...
Page 15: ...e one flathead ESD screw C 3 Hirn the pod right side up with the ROM connector facing you If an HP 75 is present remove it Lift off the top case and lay it upside down next to the bottom case CAUTION Be careful not to pull too hard on the two wire battery cable connecting the top case to the PCA The wires or connector may be damaged Figure 4 2 Power PCA Mounting Screws 4 Remove the five PCA mounti...
Page 16: ...prevent it from bending and pull the flex cable out of the connector Figure 4 3 Disconnecting the Modem Flex Cable 7 Using a 3 16 inch nutdriver remove the two nuts that secure the ROM connector shield to the bot tom case Figure 4 4 ROM Connector Shield Screws 8 Lift the PGA out of the bottom case ...
Page 17: ...ase The I O panel may come out with it 4 6 To remove the ROM connector 1 Remove the power PCA as described in paragraph 4 4 2 Remove the two screws holding the strain reliefbar in place HP 82718A Figure 4 6 ROM Connector Cable Strain Relief Bar and Connector 3 Open the zero force connector by pulling the collar out and carefully pull the flex cable out of it 4 7 Reassembly Procedure The following ...
Page 18: ...cuit when power is applied Otherwise damage to the PCA may result 3 Hirn on the HP 75 type in CAT XMEM and press rtn The words NAME TYPE LEN TIME DATE should appear in the display If this message appears in the display the ROM connector is good and is connected properly Go to step 5 If the message does not appear go to step 4 4 If the message described in step 3 does not appear in the display eith...
Page 19: ...lace protruding up into the bottom case 3 Install the I O panel in the bottom case Make sure it is seated properly behind the ten retaining pins i Panel Retaining pin 10 Figure 4 9 I O Panel Installation 4 Insert the modem flex cable into the connector on the modem PCA Make sure it is inserted all the way and is aligned correctly 5 Insert the modem flex cable into the connector on the power PCA Ho...
Page 20: ...ver and a screwdriver Figure 4 11 Securing the ROM Connector Shield 9 Connect the two and four wire battery cables Make sure that the connectors are oriented so the black wires are ontheoutside andthattheconnector ispressed alltheway onto thepins onthePCA 10 Install the five screws in the PCA Start all five screws before tightening to insure proper board alignment 11 Install the topcase on thebott...
Page 21: ...d Replacement HP82718A 15 Withthe cursor present type RUN p rtn K pod OK nn does not appear refer to section 5 for a description of any error messages that do appear 16 Remove the HP 75 and install the end retainers ...
Page 22: ...ocedures while troubleshooting and repairing the HP82718A Failure to do so could result in damage to components in the unit The diagnostic ROM is the basic tool you will use for troubleshooting the HP 82718A By executing the test programs and test commands you will be able to locate a faulty component with a good degree of accuracy Listings ofthe programs contained in the diagnostic ROM appear in ...
Page 23: ...g procedures you will come to steps in which you are told to replace one or more parts Replace the parts in the order indicated After each new part has been installed repeat the procedure from the beginning to determine whether the fault has been eliminated If the fault has not been elimi nated replace the original part Remove the two end retainers by unscrewing the six long screws in the bottom c...
Page 24: ... Plug an ac adapter into the HP 75 3 Go to table 5 3 Make sure that the batteries are fully charged and that the modem is turned off Check the voltages on the test points and replace those components that are bad as indicated by incorrect voltages Refer to the power supply schematic in section nine 4 Press Iattn I If the HP 75 does not turn on remove the ROM connector from the PCA and plug it into...
Page 25: ... 4 The HP 75 TVirns On 1 Hirn the HP 75 off and install the pod diagnostic ROM 2 Key in RUN p rtn The Pod self test runs NOTE You may wish to key in DELAY n where nis the number ofseconds delay before rthep certain components op functions ape OK op thf oJlp PCA P Paf only d a BAD eppop message is tlisplayed pepl ce the entipe If you are doing component level repair and a BAD error message is displ...
Page 26: ...rporate Parts Center Specify the following information for each part ordered a Product model and serial number b HP part number c Part description d Complete reference designation Table 6 1 Replaceable Parts Assembly Level Index Number Figure 6 1 HP Part Number Description Qty 1 82718 60005 ASSEMBLY battery 1 door 2 82718 60016 ASSEMBLY 1 bottomcase 3 82718 60907 ASSEMBLY modem 1 printed circuit 8...
Page 27: ...ex 1 9 82718 00005 CLAMP cable strain relief 1 10 82718 80009 LABEL name 1 11 0610 0001 NUT hex 2 2 12 2340 0002 NUT 4 40 4 13 82001 60001 PACK battery 2 14 82718 40010 PLATE I O 1 15 82718 40005 RETAINER left 1 16 82718 40006 RETAINER right 1 17 0520 0306 SCREW 4 40 0 188 inch 1 18 0520 0128 SCREW 2 56 0 25 inch 2 19 0520 0308 SCREW 4 40 0 25 inch 1 20 2200 0209 SCREW 4 40 0 375 inch 12 21 0520 0...
Page 28: ...HP 82718A Replacement Parts 6 3 i h Figure 6 1 HP 82718A Expansion Pod Exploded View 6 6 ...
Page 29: ...19 20 44 45 0160 5471 Capacitor 0 1 uF 25V 4 J3 1252 0085 Connector 20 pin 1 Q3 1854 0739 Transistor 1 R14 0698 8824 Resistor 560K 5 1 R15 22 0757 0442 Resistor lOK 5 2 R23 0757 0283 Resistor 2K 5 1 U2 1820 3652 Microprocessor 63A01 1 U15 1820 1563 Integrated Circuit MM74C14 1 Y1 0410 1410 Crystal 4 9152 MHz 1 These components are used to replace surface mounted devices ...
Page 30: ...M IC37I H O D U U U U LeieJ I ...
Page 31: ...Section 7 Diagrams 7 1 Introduction This section contains the schematic diagrams you will find helpful for troubleshooting and testing the HP 82718A Expansion Pod ...
Page 32: ......
Page 33: ...if vss XTAL EXTAL NNI ii gsa STsr P2I ICPT P21 OCNP P22 BOCLK I Ci Uatd only Kith 27C32 EPRON units I IRFO I lAll AS SCI Cll 9 P8QN VHUiS WMIA14 WiHC NC W AS AA 1lAl W 1A9 WSIAB WiBKD 1112 U UIB 27C32 B5 IIAB 1A11 Diagranu 7 6 Figure 7 2 Power PCA Modem Interface ...
Page 34: ...HP82718A HP75 BATTERY CONTACTS Battery Pod Battery 2 CONNECTOR J1 6 BH Diagrams 7 7 HOHON Figure 7 3 Power PCA Power Supply SoluijBiaUe ...
Page 35: ...18 U19 U17 ROM connector firmware is displayed and the unit resets Q3 in the power supply HP 75 system ERROR 16 is displayed There is not enough memory left in the HP 75 to run the pod diagnostic rom U18 BAD U18 J3 ROM connector rom U19 BAD U19 J3 ROM connector 1LH7 BAD block move MEM 2 bytes indirect BAD and Ad dress lines BAD 0 1 all are displayed U20 U17 0 ram 1 BAD U20 U17 ram 2 BAD U21 U17 ra...
Page 36: ...after BM up U17 U20 P not updated after BM down bIockmove MEM U20 U17 address lines BAD xxx yyy U20 U17 1LL6 BAD Yl C7 C8 U2 U15 U28 R14 R15 R22 R23 C19 C20 C44 C45 1LL6 rom U18 BAD rom U19 J3 ROM connector 1LH7 BAD and 1LH7 BAD all appear no MEMIC chips U17 J3 A B C D BAD U17 A B C D not imique U17 H D l H BAD U17 adders BAD U17 MEMIC didn t select U17 decoders chipenables BAD U17 U20 27 sum set ...
Page 37: ...d pod BAD all appear together turn the HP 75 off andmonitor U2 40 with an oscilloscope while turning the HP 75 on If Then The signal changes from a dc level to an ac clock 1 2 MHz and remains as a clock signal The signal remains at a dc level U2 or U28 is bad Replace Yl C7 C8 U15 R14 R15 R22 R23 C19 C20 C44 C45 ...
Page 38: ...est depends on the the fact that there are 64 ram chips on 4 MEMIC chips 64 bits 8 hytes ADDRESS LINES test the address lines alg fill first 8K ram chip with zero addr 0 loop M addr PE for 0 0 to 8K if o addr then if M o PF then error address lines BAD addr o else if M o 0 then error address lines BAD addr o next o M addr 0 reset ram if addr 0 then addr 1 else addr addr addr while addr 8K done Not...
Page 39: ...m HEWLETT PACKARD Portable Computer Division 1000 N E Circle Blvd Corvallis OR 97330 U S A Reorder Number Printed In U S A 6 84 82718 90006 82718 90006 ...
