Service manual

Theory
3-15
I/O PCBA
The I/O PCBA holds those external connectors that cannot fit on the CPU PCBA and provides for
internal connections to the touchscreen and video connectors. The I/O PCBA contains active
components used for buffering touchscreen and C-Sync signals when the unit is attached to a
91416-B. The I/O PCBA also contains PCBA connectors, EMI filters, resistors, and capacitors.
IR Touchscreen Connector (90385 Only)
Figure 3-7: 90385 touchscreen connector pins
External SDLC
connector
HD 26-pin, female, D-Sub
1- NC
2- GND
3- NC
4- GND
5- NC
6- GND
7- NC
8- NC
9- CLK+
10 - GND
11 - NC
12 - GND
13 - NC
14 - GND
15 - NC
16 - NC
17 - DATA+
18 - CLK-
19 - NC
20 - GND
21 - NC
22 - GND
23 - NC
24 - NC
25 - NC
26 - DATA-
Table 2: External Connectors on the CPU PCBA (continued)
Connectors Description
SDLC
front view
19
10
1926
18
front view
171
18 34