Adjustment Instructions; Deck Adjustment; Circuit Adjustment - LG KE-14P2B Service Manual

Notes;
(Adjustments must be performed by the following procedures)
1. It is recommended that an isolation transformer be used
when servicing this chassis to prevent electric shock and
damage to test equipment.
2. The ac line voltage must be maintained at 230 vac, +- 10%,
50/60 hz.
3. Prior to making any adjustments, the receiver must be
operated for 10 minutes.

1. DECK ADJUSTMENT

1. Deck Transit System Adjustment
1-1. Necessary Instruments
1) TAPE for SP
2) Oscilloscope
3) 10:1 Probes 2EA
4) Adjustment Driver
(P2, P3, X-distance (NUT), Audio (NUT) control)
5) RMS Meter (Audio Level Meter)
1-2.Preliminary Steps
1) Connect CH 1 of the oscilloscope to J123 (H/SW) on the main
PCB. Trigger on this channel.
2) Connect CH 2 of the oscilloscope to J158 (RF) on the main
PCB. Monitor this waveform when preceding with step 4.
3) Play an alignment tape.
4) When the "auto Trk" caption appears on screen, press the
TRK up (+) button on the RCU to initialize the manual
tracking feature.
5) If manual tracking differs from auto tracking, precede with
steps 1-3 (RF Linearity) and 1-4 (X-Distance Adj.).
P2
DRUM
FE HEAD
P1
ARM
TENSION
P0
SUPPLY
REEL
<Adjust Parts Location>
1-3. RF linearity check and adjustment
1) Adjust P2 & P3 so that the RF ENVELOPE waveform is
maximum and stabilized .
2) Check if the ENVELOPE waveform is at its maximum size
by pressing TRK UP(+) and DOWN(-) button one step.

ADJUSTMENT INSTRUCTIONS

AZIMUTH
P3
SCREW
X-DISTANCE
CONE POINT
ADJUST SCREW
SCREW
A/C HEAD
HEIGHT ADJUST NUT
A/C
P4
HEAD
CAPSTAN
PINCH
ROLLER
TAPE
TAKE-UP
REEL
P2
P2 POST ADJUST
P3 POST ADJUST
<Adjustment waveform>
1-4. X-Distance Adjustment
1) Turn the Cone Screw of the DECK left or right so that the
RF waveform is maximum.
2) Check if the RF waveform satisfies the linearity by
pressing TRK UP(+) and DOWN(-) button one step.
CAUTION: If the RF waveform becomes maximum with
the Cone Screw more than 2 turns, its out of adjustment.
(2 turns; 720¡£ )
1-5. Audio Level Check and Adjustment
1) Connect "+" terminal of RMS Meter (Audio Level Meter)
to J108 on MAIN PCB AUDIO OUT and "-" terminal to GND,
respectively.
2) Play the 1khz and 7khz segments on the alignment tape
and confirm if the spec is meet in item #3. If not adjust
the azimuth screw to meet this spec.
3) Audio Level Spec:
<Adjustment Waveform>

2. CIRCUIT ADJUSTMENT

T/UP
ARM
1. PG Adjustment
1-1. Necessary Instruments
1) Alignment tape SP
2) Oscilloscope
3) 10 : 1 Probe
1-2.Adjustment
1) PLAY exclusive use of SP tape. (2HD: NORMAL TAPE)
2) Connect CH 1 of the Oscilloscope to J123 (H/SW) on the
MAIN PCB and VOL/DIV to 1V Range and Trigger the
Oscilloscope.
3) Connect CH 2 of the oscilloscope to J241 (Video Out) on
the main PCB and set the VOL/DIV to 500mV Range.
4) Set TIME/DIV of oscilloscope to 50 ¥s Range.
5) Adjust VR01 so that V-sync Falling Edge of Video signal
become 412 ¥sec¡ 20¥sec.
P3
1KHz ; 0.5 ¡ 0.1Vrms
6KHz ; 1K ¡ 1.5dB
Adjust waveform
3-5