Routing the Touchscreen Cables
The internal cables that carry the analog touchscreen signals are subject to interference from various sources within the display. The routing of these cables should avoid the following areas, listed in order of importance:
•flyback
•anode
•inverter section of the power
•
•RGB video drive section of the display
•video input cable
•horizontal and vertical oscillator/drive
Once acceptable cable positioning is determined, tie the cable down to avoid movement during shipment. In addition to careful cable routing, other EMI suppression techniques may be necessary to satisfy agency approval requirements. Use ferrite beads or other radio frequency (RF) suppression elements, additional shielding, and different grounding techniques as needed. Also, attach all excess cable/service loops as close to the chassis as practical to reduce noise emissions.
Reassembling the Monitor
With the touchscreen mounted, and the cable routing and exterior interface determined, the display must be reassembled. Reassembly is generally in reverse order of disassembly. Beware of potential clearance problems between the bell of the CRT and the electronics chassis, as shorts in this area can produce catastrophic failures of the display. Also, if the inside surface of the back case is painted with a conductive coating, watch for shorts between the CRT circuit board and the rear of the back case, as these can also produce disastrous results.
When the electronics chassis is reinstalled, the CRT circuit board is usually carried along with it. It is often advisable to have a second person assist you, to insure that this circuit board and various other cables do not interfere with the yoke or neck of the CRT. Safety glasses, gloves, heavy protective clothing, and caution are strongly advised for all participants.
