Panasonic TC-14RM12L P Service Manual

Panasonic TC-14RM12L P Service Manual Manual pdf 15 page image

- 15 -TC-14RM12LP/TC-14RM12LP(.)/ TC-20RA12LP/TC-20RA12LP(.)/TC-20RM12LP/TC-20RM12LP(.)ADJUSTMENTSNECESSARY INSTRUMENTS:ITEM / PREPARATION PROCEDUREBUZZING CONFIRMATION (AUDIO CIRCUIT)1. Connect the oscilloscope with a 7kHz filter between thespeakers terminals L+ to G4-4, L- to G4-3, R+ to G4-1and R- to G4-2.2. Adjust volume control to maximum.3. Adjust the others controls as above:SOUND MENU DIALOGEQUALIZER NORMALBALANCE CENTERHYPER BASS OFFLOUDNESS OFFAVL OFFSURROUND OFFCONFIRMATION:1. Supply a colorbar signal with local frequency adjustedand the AFC ON (Channel with sound bearer and withoutmodulation).2. Assure that the width in the buzzing waveform is smallerthan 500 m Vp-p.RF AGC ADJUSTMENT1. Supply a color bar PHILIPS pattern and adjust the RFinput signal of 69 dB mV (75W opened channel 7 RFfreq.: 175.25 MHz).2. Connect the digital multimeter in TPA15.ADJUSTMENT:1. Select “RF AGC” on “CHK2” service mode.2. Adjust "RF AGC" by pressing VOL(+) or (-) until obtaining2.2±0.1V in TPA15.3. Increase the input level by +2 dB and confirm that thevoltage decreases in TPA15.CONFIRMATION1. Connect a voltage meter between TPA16 and ground andconfirm that the voltage +B is within a range of 141,0V± 2V2. Connect a high frequency voltage meter (VRMS) amongthe heater, and confirm that the voltage is according tothe table below:3. Connect the high voltage meter in the CRT anode pin,and confirm that the high voltage is be among 25,2~23KVfor 14” CRT and 27,2~25KV for 20" CRT .ANODE AND HEATER VOLTAGE CONFIRMATION1. 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 isnecessary to use an electrostatic meter type to verify thevalues)14” 6,15 ± 0,25 Vrms20” 6,15 ± 0,25 VrmsPROTECTION CIRCUIT (SHUTDOWN)CONFIRMATION OF OPERATION1. Supply a crosshatch pattern signal and adjust theCONTRAST and BRIGHT DAC controls to minimum.(Ibeam=0 μA)CONFIRMATION:1. Connect the voltmeter in TPA22 and confirm that thevoltage is smaller than [A].2. Connect a DC source in TPA22 and confirm that theprotection circuit doesn't act when the voltage is [B].3. Confirm that the protection circuit acts with smaller voltagethan [C].ConditionABC14”22,823,926,720”23,324,527,4smaller than500 m Vp-p7K Hz Filter• CW GENERATOR• DUAL-TRACE OSCILLOSCOPE VOLTAGE RANGE0.001 V TO 50 VDIV.FREQUENCY RANGE DC TO 50 MHZPROBES 101, 11• SPECTRUM ANALISER• NTSC VIDEO PATTERN GENERATOR• DVM (DIGITAL VOLT METER)• POWER SUPPLY DC 30V• ATENUADOR• ISOLATION TRANSFORMER (VARIABLE)• DEGAUSSING COIL• WHITE PATTERN GENERATOR• AUDIO GENERATOR