Elo TouchSystems AccuTouch 821615-000, Product Manual

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E l o E n t u i t i v e T o u c h m o n i t o r
Removing the Electronics Chassis
Continue disassembling the monitor until the face of the CRT is completely
exposed. The degree of disassembly required will vary from monitor to monitor.
Normally the next step will be to remove the electronics chassis from the
monitor. 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 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:
• 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 CRT. MPR II-compliant monitors may have additional cables
and connectors on the yoke.
• 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 may have two separate coils.
• A one- or two-wire ground cable connected between the CRT circuit board
and a ground strap. This strap is a long, annulated, braided wire which is
spring tensioned to maintain contact with the bell of the CRT.
• Various cables connected to the power switch, pilot light, front panel
controls, etc.
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.
Another preliminary step in determining touchscreen-monitor compatibility
should 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 standard technique for mounting the touchscreen involves moving the CRT
back in the monitor chassis, there must be enough clearance between
components on the chassis and the CRT after allowing for about 1/4-inch (6
mm) movement of the CRT towards the rear of the chassis. Failure to allow for
this clearance requirement may result in mechanical damage later (especially in
shipping). It may also 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 is usually painted with a conductive coating that
is grounded to the chassis through the braided wire ground strap. Repositioning
or substituting low profile components may be an option. Contact Elo Technical
Support for assistance (1-800-557-1458 x6).