Adjustments - Panasonic TC-14RM12L P Service Manual

ADJUSTMENTS

NECESSARY INSTRUMENTS:
• CW GENERATOR
• DUAL-TRACE OSCILLOSCOPE VOLTAGE RANGE
0.001 V TO 50 VDIV.
FREQUENCY RANGE DC TO 50 MHZ
PROBES 101, 11
• SPECTRUM ANALISER
• NTSC VIDEO PATTERN GENERATOR
ITEM / PREPARATION
RF AGC ADJUSTMENT
1. Supply a color bar PHILIPS pattern and adjust the RF
input signal of 69 dB mV (75W opened channel 7 RF
freq.: 175.25 MHz).
2. Connect the digital multimeter in TPA15.
BUZZING CONFIRMATION (AUDIO CIRCUIT)
1. Connect the oscilloscope with a 7kHz filter between the
speakers terminals L+ to G4-4, L- to G4-3, R+ to G4-1
and R- to G4-2.
2. Adjust volume control to maximum.
3. Adjust the others controls as above:
SOUND MENU
EQUALIZER
BALANCE
HYPER BASS
LOUDNESS
AVL
SURROUND
ANODE AND HEATER VOLTAGE CONFIRMATION
1. Supply a crosshatch signal.
2. Adjust the current beam to zero. (0 beam).
3. Adjust "SCREEN VR" and "CONTRAST" to minimum.
Note:
(When using a high voltage meter resistive type, it is
necessary to use an electrostatic meter type to verify the
values)
PROTECTION CIRCUIT (SHUTDOWN)
CONFIRMATION OF OPERATION
1. Supply a crosshatch pattern signal and adjust the
CONTRAST and BRIGHT DAC controls to minimum.
(Ibeam=0 µA)
DIALOG
NORMAL
CENTER
OFF
OFF
OFF
OFF
7K Hz Filter
TC-14RM12LP/TC-14RM12LP(.)/ TC-20RA12LP/TC-20RA12LP(.)/TC-20RM12LP/TC-20RM12LP(.)
• DVM (DIGITAL VOLT METER)
• POWER SUPPLY DC 30V
• ATENUADOR
• ISOLATION TRANSFORMER (VARIABLE)
• DEGAUSSING COIL
• WHITE PATTERN GENERATOR
• AUDIO GENERATOR
PROCEDURE
ADJUSTMENT:
1. Select "RF AGC" on "CHK2" service mode.
2. Adjust "RF AGC" by pressing VOL(+) or (-) until obtaining
2.2±0.1V in TPA15.
3. Increase the input level by +2 dB and confirm that the
voltage decreases in TPA15.
CONFIRMATION
:
1. Supply a colorbar signal with local frequency adjusted
and the AFC ON (Channel with sound bearer and without
modulation).
2. Assure that the width in the buzzing waveform is smaller
than 500 m Vp-p.
CONFIRMATION
1. Connect a voltage meter between TPA16 and ground and
confirm that the voltage +B is within a range of 141,0V± 2V
2. Connect a high frequency voltage meter (VRMS) among
the heater, and confirm that the voltage is according to
the table below:
14" 6,15 ± 0,25 Vrms
20" 6,15 ± 0,25 Vrms
3. Connect the high voltage meter in the CRT anode pin,
and confirm that the high voltage is be among 25,2~23KV
for 14" CRT and 27,2~25KV for 20" CRT .
CONFIRMATION:
1. Connect the voltmeter in TPA22 and confirm that the
voltage is smaller than [A].
2. Connect a DC source in TPA22 and confirm that the
protection circuit doesn't act when the voltage is [B].
3. Confirm that the protection circuit acts with smaller voltage
than [C].
Condition
A
B
C
- 15 -
smaller than
500 m Vp-p
14" 20"
22,8 23,3
23,9 24,5
26,7 27,4