PIONEER PDP-503PG/TLDPKBR
Service Manual

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6.3 ADJUSTMENT
A

VOFS/VH/IC5V Voltage Adjustment
Input Signal

Adjusting Point

Adjusting Method
VOFS (Offset voltage) adjustment Method 1 1. Make a note of the adjustment value of VOFS ADJ in factory mode. 2. Set the VOFS ADJ adjustment value to center (128). 3. Turn the VR2701 so that the voltage between K2710 (VOFS) and K2703 (SUS GND) becomes 45V. 4. Return the VOFS ADJ adjustment value to that which you wrote down in Step 1. Method 2 1. Read the adjustment value of VOFS ADJ in the factory mode. 2. Turn the VR2701 so that the voltage between K2710 (VOFS) and K2703 (SUS GND) becomes the corresponding value indicated in the table below (tolerance: ± 5):
Input Command VOF000 VOF006 VOF013 VOF019 VOF026 VOF032 VOF038 VOF045 DAC Output 0.4 0.4984375 0.61328125 0.71171875 0.8265625 0.925 1.0234375 1.13828125 1.23671875 1.3515625 1.45 1.5484375 1.66328125 1.76171875 1.8765625 1.975 2.0734375 2.18828125 2.28671875 2.4015625 2.5 Setting Voltage 25 25.9375 27.03125 27.96875 29.0625 30 30.9375 32.03125 32.96875 34.0625 35 35.9375 37.03125 37.96875 39.0625 40 40.9375 42.03125 42.96875 44.0625 45 Input Command VOF134 VOF141 VOF147 VOF153 VOF160 VOF166 VOF172 VOF179 VOF185 VOF191 VOF198 VOF204 VOF211 VOF217 VOF223 VOF230 VOF236 VOF242 VOF249 VOF255 DAC Output 2.599212598 2.71496063 2.814173228 2.913385827 3.029133858 3.128346457 3.227559055 3.343307087 3.442519685 3.541732283 3.657480315 3.756692913 3.872440945 3.971653543 4.070866142 4.186614173 4.285826772 4.38503937 4.500787402 4.6 Setting Voltage 45.94488 47.04724 47.99213 48.93701 50.03937 50.98425 51.92913 53.0315 53.97638 54.92126 56.02362 56.9685 58.07087 59.01575 59.96063 61.06299 62.00787 62.95276 64.05512 65

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VR2701 (VOFS) (Y DRIVE Assy)

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VOF051 VOF058 VOF064 VOF070 VOF077 VOF083 VOF090 VOF096 VOF102 VOF109 VOF115 VOF122 VOF128

White 100%

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Signs of improper adjustment If the VOFS Voltage adjustment is not performed properly, blinking luminance points like dots appear. If the voltage deviates greatly from the right adjustment point, the panel will turn white when lit. VH (voltage for the scan IC) Adjustment Adjust so that the voltage between K2716 (VH) and K2720 (PSUS) becomes 130V ± 0.5V. PSUS (=GNDH) is a floating GND and its electric potential is different from that of chassis GND. Be sure not to short-circuit PSUS (=GNDH) and another GND, because that may damage the unit. Signs of improper adjustment If the VH adjustment is not performed properly, blinking luminance points like dots appear. If the voltage is deviated greatly from the right adjustment point, the panel will lturn white when lit. IC5V Adjustment Adjust so that the voltage between K2707 (IC5V) and K2720 (PSUS) becomes 5.0V ± 0.1V. PSUS (=GNDH) is a floating GND and its electric potential is different from that of chassis GND. Be sure not to short-circuit PSUS (=GNDH) and another GND, because that may damage the unit.

VR2703 (VH) (Y DRIVE Assy)

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VR2702 (IC5V) (Y DRIVE Assy)

Note : Be sure to measure between specified test points.

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PDP-503PU
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