Operation Pcb - Akai VS-220EV Service Manual

VIL. ELECTRICAL ADJUSTMENT
8-1. MAIN PCB ADJUSTMENTS
Precautionary items prior to adjustments
1. The color bar generator output should be 1.0 Vp-p.
STEP | ADJUSTMENT ITEM
1. MODE and
INPUT SIGNAL/TEST TAPE
3. RESULT & REMARKS
Required following Test tapes.
IMS POSITION
1. ''E-E" Input NTSC color bar signal.
2. TV screen & VR9O1.
3. @ Depress the PROGRAM button on the
REMOTE CONTROLLER to display the
information for programming on the TV
screen.
e@ Adjust VR901 so that charactors located
IMS R
POSITION
&
ma
fic902 ¢ 902
center of the TV screen.
[text Tape [| PartNo. |
TF-530RFS AT-751775
TF-527BL AT-711880
Susi vipea
Jo SE,
ee Fn ee
ee NOUT SIN out IN
AUDIO ADJUSTMENT
. "PB" Test tape TF-527BL.
5 Audio out & VRS501.
3. —3.0+ 0.5 dBm
(TF-513L: —9.0 + 0.5 dBm)
1. "PB" Test tape TF-530RFS.
2. AUDIO OUT.
3. Confirm —6 ~ —14 dBm.
(TF-508RF: —5 ~ —11 dBm)
o TP7
s VIDEO OUT
a)
TPS
0
WHITE &
/ DARK CLIP
VRSOI
1. "REC" (1 kHz, —8dBm)
auoio—/
2. Test terminal on the
PB LEVEL
A/C Head & VR502. /
3. 29+0.1mV
/
vR502 /
A/C HEAD
a) /
eeaMIHAL
AUDIO /
REC CURRENT
AC VOLTMETER
—~ PB
a SW'ING TRACKING
POINT PRESET
1. "PB" Test tape TF-530RFS. LUMINANCE
2. TP-Video out, P204 pin 1 (SW. P) (Y) REC
for trigger signal & VR201.
3. Adjust "T" to6.5+0.5H
g
ENVELOPE
TP!
0
TP4
ae
|2| | TRACKING PRESET > a
—_—
1. "PB" Test tape TF-530RFS. oe ee
2. Test terminal P204 pin 2 (CTL), seeing | ene
pin 3 (V-SYNC) & VR202. bet =
3. Set the TRACKING Control to VR3Ol Lae
center click position. iG. ou8 IDLSV ue
e Adjust VR202 so that the phase at
at raising part of CTL pulse and ie _
V-SYNC pulse are lined up. ; Se
—- ean ees
=
a VRIOI
een CHROMA ()
REC ee
_—
1. "E-E" (stop mode) — TP3
2. TP4 (IDL Ve R301
fe Ss >
3. 5.14005 V
'
14| VERTICAL STABILITY
1. "REC" TV program and PB/PAUSE
2. TV screen & VR401
FSC
VR401
@)| verticat in,
we} STABILITY
MAIN PCB
3. Minimum vibration of still picture.
MAIN(VIDEO) PCB
14
OPERATION PCB
VIDEO ADJUSTMENT
|1f | REC CURRENT
. "REC" PAL color bar signal.
. TP801 on the PRE-AMP PCB &
VR101 (C), VR1 (Y).
3. eTurn VR1 (Y) fully clockwise.
e Adjust VR101 so that Chroma
REC current level is
45 *2 mvpp.
e Adjust VR1 so that Y REC
current level is
165 + 5 mVp-p.
RE AMP
PCB
TOSS
FSC
_ "EE"
. TP3 & VR102
. @Connect an Frequency counter to
TP3.
e Adjust VR102 so that FRQ.
counter reads
4.433619 MHz + 100 Hz.