Hitachi DZ-GX20A Service Manual page 57

Troubleshooting > Trouble Diagnosis
Operation buttons on L case do not function.
Remove the L block
Set to service position (B).
Yes
Does MENU button
function?
No
Yes
Does SELECT
button function?
No
Does DISC
Yes
NAVIGATION or
STOP/CANCEL
button function?
No
*3: When the do not function button is pressed.
Yes
TL8006 (KEY2): Does
(*3)
the voltage vary?
No
Button faulty:
Replace the L case.
List of check points
Circuit board
Symptom
(side)
TL8002 AEL (A)
TL8003 AEL (A)
TL8004 AEL (A)
TL8006 AEL (A)
Yes
TL8002 (MENU):
(*1)
0V
No
*1: When MENU button is pressed.
MENU button faulty:
Replace the L case.
Yes
TL8003 (SELECT):
(*2)
0V
No
*2: When SELECT button is pressed.
SELECT button faulty:
Replace the L case.
Yes
TL8004 (KEY1): Does
(*3)
the voltage vary?
No
Button faulty:
Replace the L case.
Replace the MAN
circuit board.
4 - 32
Lead wire
Location on
soldered
circuit board
or not
1C Need not
1C Need not
1C Need not
1C Need not
Replace the MAN
circuit board.
Replace the MAN
circuit board.
Replace the MAN
circuit board.