HEIDENHAIN ITNC 530 - Page 364

22 – 364 HEIDENHAIN Service Manual iTNC 530
Principle of the key
matrix
The keys are evaluated via a matrix. Every key is located at a crosspoint of SL (= scan line)
and RL (= return line). --> See “Key Matrix of the Keyboard Units” on page 22 – 372 or
See “Key Matrix of the Visual Units” on page 22 – 388.
Flowchart Is a line (cable, board), the key element of the keyboard or the soft-key row of the screen?
No
Yes
Use the key matrix to find a key that is
selected by the same RL line as the
defective key (and which functions in
the selected operating mode).
Any reaction?
No
Yes
The matrix lines (keyboard cable, soft-
key row, keyboard PCB) are in order.
The contact of the key is
probably defective.
The line to the matrix is interrupted.
Check the keyboard cable (measure
the cable, try replacement, etc.), the
connectors, the soft-key row or the
keyboard PCB?
Press this key.
Use the key matrix to find a key that is
selected by the same SL line as the
defective key (and which functions in
the selected operating mode).
Any reaction?
Press this key.
Inspection of the keys