Akai VS-G240EA - Page 5

. The address “Fd” and its data will be shown in the FL
display approx 2 seconds later automatically. Repeat
the presetting (steps 4 to 5) for addresses “Fd”, “F—"
and “FF” in the same manner as address “FC”.
. Press the “reset” button to disengage the model code
preset mode.
NOTE :This model code preset is absolutely necessary
when the IC404 (EEP-ROM) on the MAIN PCB is
replaced.
3) Video switching point preset
1.
2.
Engage the “test mode”.
Connect CH-1 of an oscillascope to VIDEO OUT and
CH-2 to the TP852 (V-SWP) on the PRE AMP PCB for
triggering.
. Play back the reference tape TF-530RFS (Part No.:
AT-751775). Check the seconds display of the FL
display so that “1F" (center position in the tracking
range) is indicated at this point. If not indicated, press
the "<" or “>" button on the remote contro! until “1F"
is indicated.
. Press the “REC” button during playback.
. Confirm that the switching point is positioned 6.5+0.3 H
before the left edge of the V-sync as shown.
Vv eal
ANNA ASA SSAA...
2v 100uS
NOTE :
a) Make sure that the A/C head phase adjustment has
been adjusted correctly before making video switching
point preset. (Refer to step 5-3-2)
b) This switching point preset is absolutely necessary
after the following replacements.
e When the video head drum (upper drum) is replaced.
® When the DRUM MOTOR PCB or DRUM MOTOR's
ROTARY MAGNET (ROTARY PLATE) is replaced.
When the SERVO/SYSCON MI-COM or EEP ROM IC on
the MAIN PCB is replaced.
4) Memorization of the reference RF envelope
detect voltage (I-HQ)
For correct operation of the |-HQ tape tuning system,
memorization of the reference RF envelope detect
voltage is absolutely necessary. When the VIDEO HEAD
DRUM, PRE AMP PCB or EEP ROM IC in the MAIN
PCB is replaced for any reason, memorize the reference
RF envelope detect voltage according to the following
procedure.
. Set the tape speed to “SP mode”.
2. Make a recording on the I-HQ test tape “TF-556AT”
(Part No. : AT-751822J) and rewind it to the exact point
where the recording was started.
. Set the VCR to the “test mode” then start playback.
4. Reference RF envelope detect voltage data in the
memory is displayed in 2 digits in the hours display
part of the FL display and the present envelope detect
voltage data is displayed in 2 digits in the minutes
display part (the data is displayed in hexadecimal
numbers).
5. After the auto tracking has been activated, press the
“CANCEL” button on the remote control. The present
RF envelope detect voltage data will be transferred to
the hour display 2 digits and memorized in the EEP
ROM IC.
6. Cancel the “test mode” then set the tape speed to “LP
mode” and repeat steps 2 to 5 for 2 speed models.
5) Other facilities in the test mode
1. Tracking position display
Tracking position data can be displayed on the FL
display. Data is displayed in 64 steps in hexadecimal
numbers from “OO” to “3F” in the seconds display part
on the FL display. Pressing the “TV/VCR” button on
the remote contro! during playback directly sets the
tracking to the maximum “3F” position and pressing
the “COUNTER RESET" button sets it to the minimum
“00” position.
Pressing the “PLAY” button during playback sets tracking
to the center position “1F” automatically. If “1F” does
not appear, even when the “PLAY” button is pressed,
keep pressing the “<” or “>" button on the remote
control until the “1F” appears and then press the “OK”
button to memorize the position.
2. Suspension of the tape protection system
When the VCR is not in the “test mode”, the “STILL”
mode will be released after 5 minutes in order to
protect the tape (the VIDEO HEAD DRUM stops rotating).
However, the “STILL mode” will not be released during
the “test mode”.
SERVICE
MANUAL
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