Keyboard/Rpg Problems; Keyboard Interface - Agilent Technologies 8564EC Service Manual

Spectrum analyzers

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ADC/Interface Section

Keyboard/RPG Problems

Refer to function block G of A3 Interface Assembly Schematic Diagram

(sheet 3 of 6) in the 8560 E-Series Spectrum Analyzer Component Level

Information.

A pressed key results in a low on a keyboard sense line (LKSNS0

through LKSNS7). This sets the output of NAND gate U607 high,

generating KBD/RPG_IRQ. The CPU determines the key pressed by

setting only one keyboard scan line (LKSCN0 through LKSCN5) low

through U602 and reading the keyboard sense lines.

1. If none of the keys or RPG responds, check ribbon cable, A1A1W1.

2. If an entire row or column of keys does not respond, and the RPG

Keyboard Matrix

3. Check that all inputs to NAND gate A3U607 (LKSNS lines) are high

(This cable connects the A1A1 keyboard to the A3 interface

assembly.) The keys are arranged in a row/column matrix, as shown

Table 8-3 on page

does respond, there might be an open or shorted wire in A1A1W1.

when no key is pressed. If any input is low, continue with the

a. Disconnect A1A1W1 from A3J602 and again check all inputs to

b. If any input is low with A1A1W1 disconnected, suspect A3U604,

A3U607, or A3U602.

c. Reconnect A1A1W1 to A3J602.

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