User guide

Removing the Front and Top Covers
4-46 72A-1230 Rev. F
July 22, 2005
Accessing M4100 Components
DANGER Ensure that the AC power cable is disconnected prior to removing any of
the M4100 covers. To avoid static discharge, ground yourself and the test
set before handling any circuit boards.
The following procedures require access to internal M4100 components:
• Performing internal checks
• Replacing internal components for purposes of diagnosis and repair
• Upgrading components
This section provides guidance in accessing M4100 internal components and
identifying those components and their interconnections. Subsequent
replacement procedures are detailed in ”Replacing M4100 Components”
on page 4-56.
Access to all internal M4100 components requires removal of the instrument’s
front and top covers. Access to certain components, notably many of the
instrument’s PC boards, also requires removal of the card cage cover.
Instructions for both actions are provided below.
DANGER Always disconnect AC power before gaining access to internal M4100
components. If re-application of power is necessary to perform an
internal check, follow the procedural instructions carefully to minimize
the risk of electrical shock. In particular, make certain that only
voltmeter probes come in contact with internal test points. Furthermore,
the High Voltage Test Cable and Safety Switch extension must always be
disconnected from the Transformer case during internal measurement
and inspection.
Removing the Front and Top Covers
The front and top covers must be removed to gain access to internal
components. Keep screws that are removed together in a safe location for
re-assembly.
Take the following steps to remove the covers:
1. With the power cable disconnected, snap off the front cover. To do so,
stand facing the unit and grip the edges of the front cover panel with both
hands while pulling towards you. Then, turn the unit around so that the
black rubber feet are facing you.
2. Use a flat-blade screwdriver to remove the top two rubber feet.
3. Lift the top cover up and towards the rear. Then, turn the unit around again
so that the front panel is facing the operator.