Sharp VL-H870U, Service Manual

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6-8
VL-H870U
VL-H875U
VL-H890U
VL-H870U
VL-H875U
VL-H890U
7. Adjustment of PB Y level
Measuring instrument Oscilloscope
Mode PB
Input signal Color bar (JiGWR5-8NSE)
Measuring point TL3402, TL8356(GND)
Adjustment address 3F
Adjustment level 500
±
20 mVp-p
(1) Set the color bar tape for alignment (JiGWR5-8NSE).
(2) Enter the VCR adjustment mode with an adjustment remote control, and select the address 3F.
Select the address, using the FF or REW key, and fix it with the PB key.
(3) Make an adjustment so as to get 500mVp-p between SYNC TIP and WHITE PEAK on TL3402.
Select the data, using the FF or REW key, and fix it with the PB key.
After the adjustment, press the STOP key, and exit from the adjustment address 3F.
8. Adjustment of chroma emphasis f0
Measuring instrument Oscilloscope
Mode VCR STOP
Input signal Color bar
Measuring point TL409, TL8356 (GND)
Adjustment address 38
Adjustment level Minimum chroma component
(1) Input the color bar signal into the video input/output terminal in the VCR STOP mode.
(2) Enter the VCR adjustment mode with an adjustment remote control, and select the address 38.
Select the address, using the FF or REW key, and fix it with the PB key.
(3) Make an adjustment so as to get minimum chroma component on TL409.
Select the data, using the FF or REW key, and fix it with the PB key.
After the adjustment, press the STOP key, and exit from the adjustment address 38.
Minimum chroma component
Measuring instrument Frequensy counter
Mode VCR STOP
Input signal No input
Measuring point TL7443
Adjustment address 33
Adjustment level 5.99
±
0.02kHz
9. Adjustment of Y-FM carrier (Hi-8)
(1) Input the no-signal into the video input/output terminal in the VCR
STOP mode.
At this time, do not pull out the jack on the Viewcam side.
(2) Enter the VCR adjustment mode with an adjustment remote
control, and select the address 33.
Select the address, using the FF or REW key, and fix it with the PB
key.
(3) Make an adjustment so that the frequency counter indicates
5.99MHz on TL7443.
Select the data, using the FF or REW key, and fix it with the PB key.
After the adjustment, press the STOP key, and exit from the
adjustment address 33.
Measuring instrument Ferquensy counter
Mode VCR STOP
Input signal No input
Measuring point TL7443
Adjustment address 60
Adjustment level 4.38
±
0.02MHz
11. Adjustment of Y-FM carier f0 (Normal-8)
(1) Input the no-signal into the video input/output terminal in the
VCR STOP mode.
At this time, do not pull out the jack on the Viewcam side.
(2) Enter the VCR adjustment mode with an adjustment remote
control, and select the address 60.
Select the address, using the FF or REW key, and fix it with the
PB key.
(3) Make an adjustment so that the frequency counter indicates
4.38 MHz on TL7443.
Select the data, using the FF or REW key, and fix it with the PB
key.
After the adjustment, press the STOP key, and exit from the
adjustment address 60.
Measuring instrument Oscilloscope
Mode RWC/PB (self-playback/recording)
Input signal Color bar
Measuring point TL3402
Adjustment address 34
Adjustment level 500
±
20 mVp-p
10. Adjustment of Y-FM deviation (Hi-8)
(1) Set the recordable tape.
(2) Before entering the adjustment mode,make self-playback/recording of color bar with an external output.
Measure whether the playback output at this time is 500 mVp-p on TL3402 (Hi8 TAPE).
(3) Enter the VCR adjustment mode with an adjustment remote control, and select the address 34.
Select the address, using the FF or REW key, and fix it with the PB key.
(4) When decreasing by 10 mVp-p as compared to the measurement value of (2), decrease the data of address 34 by about 5 (digit).
(Reference)
When increasing by 10 mVp-p as compared to the measurement value of (2), increase the data of address 34 by about 5 (digit).
(Reference)
Select the address, using the FF or REW key, and fix it with the PB key.
(5) Release the adjustment mode, and make self-playback/recording again. When the measuring value at this time is in the standard
value, the adjustment is completed. If it is not in the standard value, repeat the steps (2) -(4).
(6) After completing the adjustment of (5), check the adjusting value of Y-FM carrier f0 (5.99 MHz in no input).
When the measuring value exceeds the standard value of carrier f0, make an adjustment of Y-FM carrier f0 again.
500
±
20 mVp-p
500
±
20 mVp-p