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| DELL E173FP Service Manual |
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5.3.2Power Block Diagram |
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PWPC1742LGD1 |
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Function test |
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| CON205 |
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| 1 |
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| 2 |
| CN102 |
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| 1 | ON/OFF |
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| 2 |
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| R8 |
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| 3 | DIM |
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| CON206 |
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| CCFL |
| 5 |
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| 1 |
| 12V |
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| 6 |
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| 7 |
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| 8 | 5V |
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| 9 |
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| M4 |
| 10 |
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R6 | R9 |
| 11 | GND |
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| 12 |
| M2 |
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| M1 | ||||
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CCFL | 10 | Vrms METER V | Model name : | GND | R2 | V | R1 | V | ||
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| METER V | METER V | |||||
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| 5 | 100 | |||||
R7 | M3 |
| PWPC1742LGD1 |
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10 | Vrms METER V |
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| CON207 | PCB |
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| 1 |
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| R12 |
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| R4 |
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| CCFL | CON208 |
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| 560 |
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| 1 |
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| 2 |
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R10 | R13 | M6 |
| GND |
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| VR1 |
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CCFL |
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10 | Vrms METER V |
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| 10K |
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| L | N |
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R11 | M5 |
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| CN901 |
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| R5 |
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10 | Vrms METER V |
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| 100 |
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| AC IN |
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Function test step :
Step1 :
1.Adjust VR1 ( Set Vdim voltage from 0V to 5V) , then check M3 / M4/M5/M6 Vrms .
2.Check M3 / M4/M5/M6operating frequency. (
note 1 )
Note 1: M3 / M4/M5/M6 need to use two channel multimeter , such as FLUKE 45 , or use the oscilloscope check frequency.
Specification :
M1 = 12V +- 0.5V , M2 = 5V +- 0.25V
1.M3 / M4/M5/M6 = 6.5 +- 5 mV @ DIM= 5V
M3 / M4 /M5/M6= 3.0 +- 5 mV @ DIM= 0V
2.M3 / M4/M5/M6= 55KHz +- 5 KHz
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