Hitachi IJ PH Service Manual page 77

With respect to the
charging voltage
confirmation, refer to
"2.3.2 Charging voltage
confirmation".
With respect to the
excitation adjustment,
refer to "2.3.1 Excitation
adjustment".
With respect to the auto
phase gain adjustment,
refer to "2.3.4 Auto phase
gain adjustment".
3.3.2 EZJ106 board (NH board)
[Function]
- Control of nozzle (charging voltage control, excitation voltage, APH detection, PTC
control and the like) is performed.
[Setting of switch/check point/LED display and the like]
- Setting of switch
ＤＳＷ１
ＤＳＷ2
- Check point/LED
Reference Name
number
TP1 APH signal
TP3 GND
TP12 Charging
signal
TP13 GND
TP14 Excitation
signal
TP15 PTC signal
LED1 APH signal
[Note at the replacement]
- When replacing boards, be sure to turn off the power.
- Set up DSW1 and DSW2 according to the nozzle diameter.
- After replacing the board, confirm the charging voltage.
- Perform the excitation adjustment.
- Perform the auto phase gain adjustment.
[EZJ106 board external views]
Two studs for fixing
a protective cover
DSW1
LED1
Protective
cover
Three setscrews
Caution against an electric shock
The EZJ106 board has a portion where high voltage is applied.
the adjustment in a state where the Electric Component cover is opened, be fully
careful about an electric shock.
Nozzle size
６５μm
Mark
Mark
Charged amount detection signal of ink drops
Ground (for APH)
Character signal charging ink drops
Ground (for charge/excitation)
Sine wave signal applied to a nozzle
PTC drive signal
For APH signal check with eyes
(Marked side）
(Marked side）
DSW2
3-22
Content
Three setscrews
TP14: Excitation signal
TP13: Ground
Three setscrews
TP12: Charging signal
TP3: Ground
TP1: APH signal
TP15: PTC signal
Two studs for fixing a
protective cover
When performing