Removing The Electronics Chassis - Elo TouchSystems IntelliTouch Ultra Product Manual

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Chapter 4 - Component Installation Chapter 4 - Component Installation

Removing the Electronics Chassis

Removing the Electronics Chassis
Continue disassembling the display until the face of the CRT is completely Continue disassembling the display until the face of the CRT is completely
exposed. The degree of disassembly required will vary from display to display. exposed. The degree of disassembly required will vary from display to display.
Normally the next step will be to remove the electronics chassis from the display. Normally the next step will be to remove the electronics chassis from the display.
This requires removal of a small circuit board that is usually plugged into the This requires removal of a small circuit board that is usually plugged into the
socket on the end of the CRT. The circuit board is often glued to the CRT socket socket on the end of the CRT. The circuit board is often glued to the CRT socket
with a soft adhesive which must be cut away to remove the board. Several cables with a soft adhesive which must be cut away to remove the board. Several cables
must also be unplugged from the electronics. Typically these cables are: must also be unplugged from the electronics. Typically these cables are:
Four wires from the yoke of the CRT, typically in a single four-pin connector. Four wires from the yoke of the CRT, typically in a single four-pin connector.
• •
The yoke is the copper wire and magnet assembly at the base of the neck of The yoke is the copper wire and magnet assembly at the base of the neck of
the CRT. MPR II-compliant monitors may have additional cables and the CRT. MPR II-compliant monitors may have additional cables and
connectors on the yoke. connectors on the yoke.
A two-wire cable from the degaussing coil. This coil may be attached to the A two-wire cable from the degaussing coil. This coil may be attached to the
• •
CRT, or be laying out of sight between the CRT and the bezel. Some monitors CRT, or be laying out of sight between the CRT and the bezel. Some monitors
may have two separate coils. may have two separate coils.
• • A one- or two-wire ground cable connected between the CRT circuit board A one- or two-wire ground cable connected between the CRT circuit board
and a ground strap. This strap is a long, uninsulated, braided wire which is and a ground strap. This strap is a long, uninsulated, braided wire which is
spring-tensioned to maintain contact with the bell of the CRT. spring-tensioned to maintain contact with the bell of the CRT.
Various cables connected to the power switch, pilot light, front panel controls, Various cables connected to the power switch, pilot light, front panel controls,
• •
etc. etc.
Other cables may have to be unplugged from the electronics chassis. The need for Other cables may have to be unplugged from the electronics chassis. The need for
this may not be apparent until the chassis is removed, as instructed below. this may not be apparent until the chassis is removed, as instructed below.
Another preliminary step in determining touchscreen/display compatibility should Another preliminary step in determining touchscreen/display compatibility should
be performed at this point. Before removing the electronics chassis, note the be performed at this point. Before removing the electronics chassis, note the
clearance between the chassis components and the bell of the CRT. Since the clearance between the chassis components and the bell of the CRT. Since the
standard technique for mounting the touchscreen involves moving the CRT back standard technique for mounting the touchscreen involves moving the CRT back
in the display chassis, there must be enough clearance between components on the in the display chassis, there must be enough clearance between components on the
chassis and the CRT chassis and the CRT
after after
CRT towards the rear of the chassis. Failure to allow for this clearance require- CRT towards the rear of the chassis. Failure to allow for this clearance require-
ment may result in mechanical damage later (especially in shipping). It may also ment may result in mechanical damage later (especially in shipping). It may also
cause electrical damage from shorts between "live" components on the chassis, cause electrical damage from shorts between "live" components on the chassis,
such as heat sinks or uninsulated component leads, and the bell of the CRT which such as heat sinks or uninsulated component leads, and the bell of the CRT which
is usually painted with a conductive coating that is grounded to the chassis is usually painted with a conductive coating that is grounded to the chassis
through the braided wire ground strap. Repositioning or substituting low profile through the braided wire ground strap. Repositioning or substituting low profile
components may be an option. Contact Elo Technical Support for assistance. components may be an option. Contact Elo Technical Support for assistance.
After disconnecting any necessary cables, remove the screws that attach the After disconnecting any necessary cables, remove the screws that attach the
electronics chassis to the bezel. Note the bezel is essentially where all parts of the electronics chassis to the bezel. Note the bezel is essentially where all parts of the
mechanical assembly are attached, unless you have a rare unit that has an internal mechanical assembly are attached, unless you have a rare unit that has an internal
allowing for about 0.25-inch (6 mm) movement of the allowing for about 0.25-inch (6 mm) movement of the