Main / Sub Color Level & Crt Cutoff - Mitsubishi WS-48515 Service Manual

MODELS: WS-48515 / WS-55515 / WS-55615 / WS-55815 / WS-65515 / WS-65615 /WS-65815 / WS-73615
[Video Circuit]
3. Main/Sub Color Level
Oscilloscope
Measuring
Instrument
JA pin 29 & JA pin 44
Test Point
------
Ext. Trigger
------
Measuring
Range
Color Bars
Input Signal
Input Terminal
Video
[CRT Circuit]
4. CRT Cutoff
Measuring
Oscilloscope
Instrument
Test Point TP6R, TP6G, TP6B
Ext. Trigger ------
Measuring
50V/Div. 2msec/Div.
Range
Input Signal
None
Input Terminal
Video Input
CRT Cutoff Presets
VC Function
Item Abbr.
1 SBRT
2 SCT
3 SCON
4 RDRH
5 GDRH
6 BDRH
7 CTRH
8 CTGH
9 CTBH
Purpose:
Symptom:
1. Supply an NTSC signal to an External Video Input.
2. Select the NTSC signal as the source for both the main and sub pictures.
3. Connect an oscilloscope to connector JA pin 29.
4. Activate the Adjustment mode.
5. Select Item "04 COLM" in the Main Matrix Function.
6. Adjust data so the signal is 0.66 Vp-p ~ 0.71 Vp-p.
(If it cannot be adjusted within this range, set to the lower value)
7. Connect an oscilloscope to connector JA pin 44.
8. Select item "04 COLS" in the Sub Matrix Function.
9. Adjust so Sub = Main (+0.0V - 0.05V).
Purpose
Symptom:
Note: Use the Expand mode (full screen)
1. Select an External Input with no signal.
2. Enter the Adjustment Mode, VC Function.
3. Press "1", automatically blanks the screen and sets COL to 0.
Note: If the screen goes blue, turn off Video Mute.
4. Set the data to the values given in the table below.
5. Connect the oscilloscope to TP6R.
6. Adjust the Red Screen VR so the black level is 175V, as shown below, or
179V ±1VDC using an DC Voltmeter.
7. Repeat Steps 4 and 5 to set the Blue and Green Screen VRs, using
TP6G and TP6B.
Note: White Balance must be performed
after this adjustment.
Setting
20
31
7
31
37
31
31
25
31
To match the sub picture color to that of the main picture.
Main and sub pictures colors differ.
CIRCUIT ADJUST MODE
Activate ........ MEN U-2-4-5-7
Function ... ......... .....AUD IO
Item No. ...... ...........VIDEO
Adjus t Data ...........AD JU ST
Save Data .... ......... ENTER
Exit ......... .....MEN U (twice)
To set the cutoff point for all three CRTs.
Monochrome has a color tint, or incorrect brightness.
Page 41
CIRCUIT ADJUST MODE
Activate ........ MEN U-2-4-5-7
Function ... ......... .....AUD IO
Item No. ...... ...........VIDEO
Adjus t Data ...........AD JU ST
Save Data .... ......... ENTER
Exit ......... .....MEN U (twice)