I
KEYBOARDSCANOR KEYBOARD
INTERRUPT CIRCUITRY BAD.
START
t
TURN UNIT OFF, THEN BACK ON.
WHILE UNIT IS STILL DISPLAY-
ING DASHES, PRESS BAND AND
HOLD IT IN. WHEN THE DISPLAY
GOES TO ZEROS, IS THE BAND
LIGHT FLASHING?
KEYBOARD OR KEYBOARD
BUFFER BAD.
YES
WITH SCOPE LOOK AT
A201 B-E4
(I.F. THRESHOLD)
IS IT A TTL LOW?
N
0
I
ENTER KEYBOARD TEST BY
MOMENTARILY TYING
AlO8TPl
TO A105TP8. PRESS ANY KEY.
DOES THE DISPLAY SHOW
CXX (XX
=
COORDINATES)?
(Figure 6-1
0)
YES NO
I.F. AMP OR
I.F.
-1
THRESHOLD BAD.
I
I
I
R F LEVEL FROM I.F. AMP BAD,
POWER METER ZERO DAC BAD,
OR POWER METER BAD.
GO TO POWER METER TROUBLE-
SHOOTING TREE. Figure 6-21.
YES
Figure
613.
Key board
N
0
Scans by ArtekMedia © 2007
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