Service manual

30
VL-AH150U
VL-AH160U
6-3-6. Adjustment of audio circuit
1. Adjustment of filter f0
Measuring instrument Oscilloscope
Mode PB
Input signal (tape) JiGWR5-5NSP
Measuring terminal TL605/AUDIO.OUT
Adjustment address 33
Set value Clear the waveform
Audio Check
Checking of self-recording/playback
1) Input the audio signal (400Hz, -8dBs) into the Audio line IN/
OUT terminal, and record.
2) Connect the valve voltmeter (oscilloscope) to the Audio line
IN/OUT terminal.
3) Play back the record, and ascertain that the output waveform
level is -8 dBs ± 4 dBs (580 to 1370 mVp-p on the oscillo-
scope).
4) If there is any deviation from the specified value, perform
adjustment again as stated in items 1) above, and check again
the self-recording/playback level.
1) Set the alignment tape (JiGWR5-5NSP).
2) Using the adjustment remote controller (RRMCG0033TASA),
set the VCR adjustment mode, and set the address “33” with
the operation switch (FF/REWIND key).
3) Play back the standard tape.
4) Using the operation switch (FF/REWIND key), make an
adjustment so that the most clear playback waveform is
obtained on TL605.
5) Press the operation switch (PLAYBACK key) to write the
data.
6) Press the operation switch (STOP key) to exit from the
address “33”.
(The address “33” blinks.)
Measuring instrument Valve Voltmeter (oscilloscope)
Mode REC →PB
Input signal (tape) 400 Hz, -8 dBs (872 mVp-p)
Measuring terminal Audio IN/OUT
Adjustment address —
Set value -8 dBs ± 4 dBs (580 to 1370 mVp-p)
2. Dac full-Scalle adjustment
Measuring point TL1801 (G-OUT)
Address 039
Mode VCR
Adjusting method 1) Set the data of address 082 changed to 80, address 0A2 changed to 00, address 0A5 changed to 80.
2) Connect TL3804 to P-CON 3.1V.
3) Connect the Digital voltmeter to TL801 and adjust the DC volt.
4) Set the data of address 082 changed to 40, address 0A2 28. (Restore)
Adjustment standard 0.78V ± 10mV
Remarks ———————
VCR ADJ
Address Data(3 type) Data(3.5 type)
50 8F 95
51 8A 90
52 6F 74
1. Inverter input Voltage Setting
6-3-7. Adjustment of LCD display circuit
Adjustment procedures and connections are the same as with the VCR section. (Refer to item 6-3-3)
3. R-W/B adjustment
Measuring point TL3814 (G-OUT) TL3813 (R-OUT)
Address 090
Mode VCR
Adjusting method 1) Set the data of address 082 at the address 80.
2) TL3814 (G-OUT): Oscilloscope CH1
TL3813 (R-OUT): Oscilloscope CH2
3) Adjust P-P of TL3813 becomes bigger 0.15V than TL3814.
4) Set the data of address 082 at the address 40. (Restore)
Adjustment standard ±0.1Vp-p
Remarks ———————
G R
Measuring point TL3814 (G-OUT) TL3815(B-OUT)
Address 092
Mode VCR
Adjusting method 1) Set the data of address 082 at the address 80.
2) TL3814 (G-OUT): Oscilloscope CH1
TL3815 (B-OUT): Oscilloscope CH2
3) Adjust P-P of TL3815 become bigger 0.1V than TL3814.
4) Set the data of address 082 at the address 40. (Restore)
Adjustment standard ±0.1Vp-p
Remarks ———————
4. B-W/B adjustment