Name: HP HP-87
Brand: HP
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Contents2
Illustrations List7
Tables List9
General Information10
Product Description10
Specifications12
Identification14
Safety Consideration15
Servicing17
Using this Manual18
Recommended Tools18
Troubleshooting22
System Overview23
Block Diagram25
Troubleshooting Overview28
Keyboard Assembly Propped up View29
Removing and Inserting Socketed Ics30
Setup33
Socketed Ics33
Initial Troubleshooting34
Ics Indicated by {CPU BAD? N or RAM BAD!} Message37
No Turn-On38
Power Supply, PWO, and Clock Test Points40
Service Roms41
Clock Waveforms41
Self-Test42
Running a Service ROM Test43
System Self-Test Results43
Error Messages45
Service ROM Tests46
Troubleshooting with the System Test47
Results of the System Test47
RAM/ROM Test Diagnosis48
Beeper Test Diagnosis49
CRT Test Diagnosis49
Timer Test Diagnosis50
Keyboard Test Diagnosis50
Service ROM IC Messages51
Troubleshooting with the Cycle Test53
How to Run the Cycle Test53
Using the Heat Test53
Results of the Heat Test54
Troubleshooting with the CPU Test54
Results of the CPU Test55
Troubleshooting the Control and Bus Lines55
Troubleshooting with the RAM Test56
Control of Bus Line Failure Isolation56
Results of the RAM Test57
Troubleshooting with the ROM Test57
Results of the ROM Test58
Troubleshooting with the External ROM Test58
Results of the External ROM Test59
Keyboard Troubleshooting60
How to Run the Keyboard Test60
Enhancement ROM Codes60
Results of the Keyboard Test61
Key Sequence for Keyboard Test62
No Key Entry69
Wrong Character Entered70
Key Stuck73
Mnemonics and Key Lines for Keys Expected74
Key(S) Corresponding to Character Entered79
Troubleshooting with the Timer Test84
Results of the Timer Test84
Troubleshooting the CRT84
Results of the CRT Test85
CRT Test Patterns87
CRT Adjustments89
Checking Whether the Display Is Pincushioned92
CRT Test Pattern Overlay in Position92
CRT Adjustment Procedures93
Skew94
Horizontal Centering97
Size98
Vertical Centering and Height98
Power Supply Troubleshooting99
Focus99
PWO and Clock Failure Isolation102
Troubleshooting with the Short HP-IB Test104
Results of the Short HP-IB Test104
Troubleshooting with the Long HP-IB Test105
Results of the Long HP-IB Test106
Troubleshooting with the External RAM Test106
Results of the External RAM Test107
Troubleshooting with the Beeper Test108
Results of the Beeper Test108
Using the QA Test108
Results of the QA Test109
Disassembly and Reassembly110
Removing and Tightening Screws111
Cable Interconnections112
Special Handling for Keyboard Assembly Cables112
Connecting a Cable112
Removing a Trapped Cable113
Aligning Cable Contacts113
Cable Connected Properly114
Cable Misaligned114
Cable Connected with Edge Folded over115
Replacing Assemblies and Case Parts116
Separating the Top Case from the Bottom Case118
Replacing the Keyboard Assembly121
Replacing a Keycap123
Keyboard View124
Replacing the Space Bar125
Replacing a Plunger and Spring127
Replacing the [Caps Lock] Key Mechanism129
Replacing Key Contacts131
Replacing a Keyboard Hinge134
Cleaning Key Contacts135
Replacing the Logic One PCA136
Replacing the Logic Two PCA138
Replacing the Power Supply PCA140
Replacing the CRT PCA142
Replacing the CRT Assembly144
Replacing the Back Panel Assembly145
Replacing the I/O PCA147
Replacing the HP-IB PCA149
Replacing Parts of the Top Case Assembly151
Replacing Parts of the Bottom Case Assembly153
To Replace the Brightness Control154
To Replace the Power Light155
Attaching the Top Case to the Bottom Case158
Replaceable Parts160
Keyboard Assembly Exploded View167
Exploded Diagrams174
Schematic Diagrams180

Brand	HP
Model	HP-87
Category	Desktop
Language	English

HP HP-87 User Manual

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HP HP-87 Specifications

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