Ikegami HTM-1990R Service Manual page 24

VIDEO PROCESS BOARD
(1) Circuit Structure
<Power Supply System>
(a) ±5.5V PC/DC Converter
<VIDEO system>
(a) YPbPr/RGB Analog Component Input
(b) RGB → YPbPr Matrix
(c) YPbPr BUS I/F
(d) Chroma (PbPr) Level Control
(e) YPbPr → GBR Matrix
(f) Contrast Level Control
(g) Character Mix/Brightness Pulse Mix
(h) Gain Control/Cut-off Control
(i) Aperture
(j) ABL Control
<SYNC system>
(a) External Sync System
(b) Sync Separator
(c) PLL-VCO
(d) Sync Process
(e) G1 Drive
<CONTROL system>
(a) Serial → Parallel I/F
(2) Adjustment Method
* Unless otherwise indicated, Input signal is HDTV and connected to YPbPr analog component. For HDTV,
there is 100% color bar (SMPTE274M), and for SDTV there is SMPTE color bar.
* The figures are images and differ from the actual signals.
<Power Supply System>
(a) TP2 [+5.5V]
Confirm in the range of +5.5±0.2V.
(b) TP3 [-5.5V]
Confirm in the range of -5.5±0.2V.
<VIDEO System (YPbPr signal adjustment)>
(a) VR305 [PB CONT NULL]
VR505 [PR CONT NULL]
For the test points TP306 (PB-2), TP506 (PR-2), Adjust the Pb and Pr signal leak to zero for monochrome
with the COLOR/MONO switch on the front panel.
(b) VR753 [CHR O/S]
For TP306 (PB-2), TP506 (PR-2), Adjust the Pb and Pr signal leak to zero when manually setting the
chroma volume on the front panel to min. The procedure is the same as the adjustment method for VR305/
VR505.
Note: Be sure to adjust VR305 and VR505 beforehand.
Set to zero.
1-B-13