Hitachi IJ PH Service Manual page 31

With respect to positions of
the board and the test pin,
refer to " 3.3.2 EZJ106 board".
3 After the completion of the automatic adjustment, when the Back key
is pressed, the auto phase detection voltage is output and therefore,
confirm the waveform by an oscilloscope.
Using the oscilloscope, confirm that the voltage of TP1 (APH signal) on the EZJ106
board is from 8 to 10 V as the maximum voltage, 2 V or less as the minimum voltage,
and is "normal" as shown in the following figure.
Normal
10ms
Noise small
4 When the automatic adjustment is not normally completed or the
waveform is "abnormality", confirm that the periphery of the gutter part is
made dirty with ink or makeup ink. When dirtiness or the like is present,
wash the periphery of the gutter part, surely dry it and then, perform the
automatic-adjustment again.
Numerical values of the auto phase gain value can also be input by a ten-key. To the
value set at present, if the auto phase gain value is set large, the gain becomes high,
whereas if it is set small, the gain becomes low. When the "Back" key is input, the
auto phase detection voltage is output and the auto phase gain value is reflected.
Abnormality
Maximum voltage
Noise large
from 8 to 10 V,
minimum voltage 2 V
or less
2-13