Sharp VT-3428X Service Manual page 44

Checking of audio playback level
AC milli-voltmeter or
Measuring
instrument
Playback
Mode
Alignment tape.(VROCPSV)
Input signal
Audio Out
Test point
(pin (11) of El connector)
Specification
level adjusting signal)
Out (pin (11) of El connector).
Checking of audio record level
AC milli-voltmeter or
Measuring
instrument
Record/Playback
Mode
Input signal 1 kHz, -8dBs (0.87Vp-p)
Test point Audio Out
(pin (11) of El connector)
Specification
Out (pin (11) of El connector).
AUDIO IN jack and put the unit A/V input
mode.
recorded portion of the tape.
specified. If it is out of specified value, verify
the bias current (Adjustment of audio bias
current below).
Adjustment of audio bias current
AC milli-voltmeter or
instrument
Record
Mode
I
Input signal
I Not required
Test point
I TP6601( + ) - TP6602( - )
Control
Specification
(Use TP6602 for ground lead.)
Checking of erase voltage and oscillation
frequency
Measuring
Oscilloscope
instrument
Mode I Record
I Full erase head
Test point
Control I T660 1
S p e c i f i c a t i o n 1 70 + 5kHz, 4OVp-p or greater
head.
erase head is approx. 4OVp-p or more and
frequency is 70 +, 5kHz.
Figure 2-2.
I
I
I
I