DFX-8500
Table
Symptom | Cause | Checkpoint | Solution |
The +37 VDC (VP1 / | The main switching FETs | Observe the voltage | Replace QF101. |
VP2) line is dead. | QF101 is defective. | waveform between the |
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| drain side and GND. |
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| IC101 is defective. | Pin 5 (FB) must be HIGH | Replace IC101. |
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| then observe the voltage |
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| waveform between pin 2 |
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| (VOUT) and pin 12 |
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| (GND) of IC101. |
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The +37 VDC (VP3) line | The main switching FETs | Observe the voltage | Replace QF201. |
is dead. | QF201 is defective. | waveform between the |
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| drain side and GND. |
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| Q201 is defective. | Observe the voltage | Replace Q201. |
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| waveform between the |
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| collector side and GND. |
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| Q202 is defective. | Observe the voltage | Replace Q202. |
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| waveform between the |
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| collector side and GND. |
|
Rev. B |
