ViewSonic E70F - 17" CRT Display Service Manual page 12

10. VERTICAL SWEEP.
10.1 VERTICAL PULL-IN RANGE.
10.1.1 APPLY SIGNAL D MODE: VGA (CHG fv = 50Hz)
10.1.2 OBSERVE THAT PICTURE LOCKS UP IN SYNC.
10.1.3 APPLY SIGNAL D MODE: 69K (CHG fv = 160HZ), MONITOR MUST BE IN SYNC.
11. CRT VOLTAGES / REGULATION / POWER
11.1 FILAMENT MEASUREMENT
11.1.1 APPLY SIGNAL A (FLAT WHITE FIELD) AT VGA MODE.
11 1 2 SET CONTRAST TO 30 FLS AND BRIGHTNESS TO THRESHOLD OF RASTER
11.1.3 MEASURE HEATER VOLTAGE AT 6.3V AND VOLTAGE MUST BE 6.3 + 0.3V.
11.2 NORMAL HIGH VOLTAGE
11.2.1 APPLY SIGNAL A (FULL WHITE PATTERN) AT VGA MODE.
11.2.2 SET BRIGHTNESS 0%, CONTRAST 0%.
11.2.3 MEASURE HIGH VOLTAGE MUST BE 26
11.2.4 APPLY SIGNAL A AT 69KHZ MODE
11.2.4. REPEAT STEP 11.2.2 THROUGH 11.2.3 THE HIGH VOLTAGE MEASURED MUST BE 26 ± 1KV.
11.3 HIGH VOLTAGE REGULATION
11.3.1 SET BRIGHTNESS 100%, CONTRAST 100%.
11.3.2 SET BEAM CURRENT TO MAXIMUM.
11.3.3 MEASURE HIGH VOLTAGE AT ANODE CAP.
11.3.4 SUBTRACT VALUE OBTAINED 11.3.3 FROM VALUE OBTAINED IN 11.2.3 THE RESULTS MUST BE
1.5KV MAXIMUM.
11.4 POWER CONSUMPTION
11.4.1 APPLY SIGNAL A (FULL WHITE FIELD) AT 69K MODE.
11.4.2 SET BRIGHTNESS 50%, CONTRAST 100%, PRESET SIZE.
11.4.3 POWER CONSUMPTION MUST BE LESS THAN 75WATTS.
12. CRT PARAMETERS
12.1 PURITY
12.1.1 INPUT FULL WHITE PATTERN AT 69KHZ MODE, SET BRIGHTNESS 50%,&CONTRAST 100% .
12.1.2 NO COLORED STAINS MAYBE VISIBLE WHEN APPLYING FULL WHITE PATTERN
12.2 DEGAUSSING
12.2.1 BEFORE SWITCHING ON THE DEGAUSSING , THE PTC101 MUST BE COLD, INTERNAL
DEGAUSSING MUST BE CAPABLE OF ACTIVATION 10 MINUTES OR LESS AFTER ANY PREVIIOUS
ACTIVATION.
12.2.2 APPLY THE SIGNAL WITH FULL WHITE PATTERN, REMOVE ALL MAGNETIC MATERIAL WITHIN
HALF A METER OF THE APPARATUS, THEN SWITCH ON THE DEGAUSSING, THE DEGAUSSING
SHOULD BE WELL.
12.3 CONVERGENCE
12.3.1 APPLY A CROSSHATC-HATCH SIGNAL. AT 69KHZ
12.3.2 WITH INSTRUMENT FACING EAST, CONVERGENCE WITHIN A CIRCLE EQUAL TO
THE DIAMETER OF THE VERTICAL HEIGHT MUST BE A ZONE 0.25mm, B ZONE 0.30mm C ZONE 0.35mm.
12.4 FOCUS
12.4.1 APPLY SIGNAL E (ALL " ME " PATTERN) AT
14.4.2 ADJUST CONTRAST FOR AN AREA OF LUMINANCE OF 28FL.
12.4.2 FOCUS MUST BE SET SUCH THAT INDIVIDUAL CHARACTER CAN BE DISTINGUISHED OVER
THE ENTIRE DISPLAY AREA.
ViewSonic Corporation
1KV.
1024x768 85Hz MODE.
Confidential - Do Not Copy
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E 70f+SB-3