Service manual

32
VL-WD250U
VL-WD450U
6. VFγ1 adjustment
Test point TL8846(VG) Address VCR ADJ E5, VCR ADJ EB
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)
Adjustment 5.6 ± 0.1Vp-p (VCR ADJ EB)
rating 3.2 ± 0.1Vp-p (VCR ADJ E5)
Examples • During IC703 or IC8802 replacement.
8. VF sub-brightness R/B adjustment
Test point TL8845(VR), TL8846(VG), TL8844(VB) Address VCR ADJ E9(VR), VCR ADJ EA(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.
7. VF sub-contrast R/B adjustment
Test point TL8845(VR), TL8846(VG), TL8844(VB) Address VCR ADJ E6(VR), VCR ADJ E7(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.
Adjustment 0 ± 40mV(VR
100
- VG
100
), 0 ± 40mV(VB
100
- VG
100
)
rating
Examples • During IC703 or IC8802 replacement.
VG
100
/VR
100
/VB
100
Vp
-
GND
Sig. center
5.6Vp-p 0.1Vp-p
3.2Vp-p 0.1Vp-p
GND
5. VF contrast adjustment
Test point TL8846(VG) Address VCR ADJ E5
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)
Adjustment 2.0Vp-p ± 0.1Vp-p
rating
Examples • During IC703 or IC8802 replacement.
2.0Vp-p 0.1Vp-p
GND