Service manual

Ultraview 1030/1050 Monitors — Service Manual
3-18
Touchscreen PCBA
The touchscreen PCBA consists of an array of infrared emitters and detectors that surround the
flat panel screen and generate an array of horizontal and vertical infrared beams over the surface
of the screen. Electronics on the CPU PCBA drive and scan the beams to detect key presses.
Refer to the <i Italic>Touchscreen Circuitry on page 3-8 for more information on touchscreen
operation.
The touchscreen PCBA also contains the front panel power switch and a diagnostics LED.
Touchscreen connections
The touchscreen PCBA connector accepts a 26-pin flat, ribbon cable from the CPU PCBA.
Table 1: Touchscreen PCBA Connector Pinout
PIN SIGNAL TYPE FUNCTION
1 IRSIG Output detect/no detect IR beam
2 gnd Input
3 +12 V Input
4 +12V Input
5 gnd Input
6 EMIT* Input 32 μs pulse low to turn on LED
7 gnd Input
8 SELECT0 Input
select bank and bit within bank to enable
SELECT[2..0] defines bit within bank
SELECT[5..3] defines bank
9 SELECT1 Input
10 SELECT2 Input
11 SELECT3 Input
12 SELECT4 Input
13 SELECT5 Input
14 gnd Input
15 LED_CHARGE Input
Charge status LED (high turns on LED, current
limited by main PCBA LM339 output pull up)
16 LED_DIAG* Input
diagnostics LED
(low turns on LED, driven 0-3.3 V by MPC860)