Sharp VL-WD250S Service Manual page 29

5. VF contrast adjustment
Test point TL8846(VG)
Mode VCR AV input
Procedure 1) Input the signal of a 3-step waveform.
2) Set VCR ADJ EB/ED to FF/00.
3) Adjust the pedestal 100% range of the waveform of TL8846 to the specified adjustment value.
4) Return VCR ADJ ED to the initial value. (Initial value: 7A)
2.0Vp-p ± 0.1Vp-p
Adjustment
rating
Examples • During IC703 or IC8802 replacement.
6. VFγ1 adjustment
Test point TL8846(VG)
Mode VCR AV input
Procedure 1) Input the signal of a 3-step waveform.
2) Set VCR ADJ EB/ED to FF/00.
3) Adjust the white 100% range of the waveform of TL8846 to 5.6±0.1Vp-p with VCR ADJ EB.
4) Hereafter, adjust the waveform to the specified adjustment value with VCR ADJ E5.
5) Return VCR ADJ ED to the initial value. (Initial value: 7A)
5.6 ± 0.1Vp-p (VCR ADJ EB)
Adjustment
3.2 ± 0.1Vp-p (VCR ADJ E5)
rating
Examples • During IC703 or IC8802 replacement.
7. VF sub-contrast R/B adjustment
Test point TL8845(VR), TL8846(VG), TL8844(VB)
Mode VCR AV input
Procedure 1) Input the signal of a 3-step waveform.
2) Adjust the pedestal 100% range of TL8846 and TL8845 to the specified adjustment value.
3) Similarly, adjust the pedestal 100% range of TL8846 and TL8844 to the specified adjustment value.
0 ± 40mV(VR
Adjustment
rating
Examples • During IC703 or IC8802 replacement.
8. VF sub-brightness R/B adjustment
Test point TL8845(VR), TL8846(VG), TL8844(VB)
Mode VCR AV input
Procedure 1) Input the white 40% signal to the AV input and standard monitor.
2) Adjust the color to be similar to the tone on the standard with VCR ADJ E9/EA.
Adjustment Standard monitor
rating
Examples • During IC703 or IC8802 replacement.
GND
Sig. center
GND
), 0 ± 40mV(VB
- VG - VG
100 100 100
Address VCR ADJ E5
2.0Vp-p 0.1Vp-p
Address VCR ADJ E5, VCR ADJ EB
5.6Vp-p
3.2Vp-p
Address VCR ADJ E6(VR), VCR ADJ E7(VB)
)
100
GND
Address VCR ADJ E9(VR), VCR ADJ EA(VB)
29
VL-WD250S/H/E
VL-WD450S/H/E
0.1Vp-p
0.1Vp-p
VG /VR /VB Vp-
100 100 100