HP E4418A Service Manual page 19

Equipment .............................................................................. 3-8
Procedure ................................................................................ 3-8
Measurement Uncertainty..................................................... 3-11
Display Brightness and Contrast Adjustment ............................ 3-12
Introduction ............................................................................ 3-12
Procedure ................................................................................ 3-12
Theory of Operation ........................................................................... 4-1
Introduction................................................................................... 4-2
A1 Power Supply ........................................................................... 4-3
A2 Processor Assembly ................................................................. 4-4
A3 Front Panel Assembly ............................................................. 4-7
A4 Interface Assembly.................................................................. 4-8
A5 Daughter Assembly ................................................................. 4-9
A6 Measurement Assembly .......................................................... 4-10
Replaceable Parts ............................................................................... 5-1
Introduction................................................................................... 5-2
Assembly Part Numbers............................................................... 5-3
Front Panel Connector Repair ..................................................... 5-5
Firmware Upgrades ...................................................................... 5-6
Downloading Firmware.......................................................... 5-6
Assembly and Disassembly Guidelines ....................................... 5-7
Removing the Power Meter Cover ......................................... 5-7
Removing the A1 Power Supply Assembly ........................... 5-8
Removing the A2 Processor Assembly................................... 5-9
Removing the A4 Interface Assembly ................................... 5-10
Removing the A5 Daughter or A6 Measurement
Assemblies .............................................................................. 5-11
Removing the A7 Fan Assembly ............................................ 5-12
Removing the Power Meter Battery (BT1)............................ 5-13
Removing the A3 Front Panel Assembly............................... 5-14
Replacing the Front Panel Power Reference Cable
Assembly ................................................................................. 5-17
Replacing the Rear Panel Power Sensor Cable
Assemblies (Options 002 and 003)......................................... 5-18
Replacing the Rear Panel Power Reference Cable
Assembly (Option 003) ........................................................... 5-20
HP EPM-441A/442A Service Guide Contents-3