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Tech Tip of The Week
Models:
D1728D-LS
Symptom(s):
No OSD Displays
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There is video but no OSD.
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| Whenever pushing a front control button, does
any pulse appear at pins 53 and 54 of IC201? |
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Whenever you push a button on the front control panel, does the voltage vary at pins 18 and 19 of IC201? | |
Check the push buttons on the front control board SW201-SW210 and CF202 |
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| Check IC201 | ||||
| Does the horizontal flyback pulse appear at pin 5 of IC103? | |
Check horizontal flyback pulse generation circuit. (D414, D415, Q413 and pin 9 of IC302) | ||
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| Does the vertical blanking pulse appear at pin 10 of IC103? | |
Check vertical blanking pulse generation circuit. (Q301, Q302 and IC104) | ||
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| Does the OSD video signal appear at pins 14 and 15 of IC103? | |
Does DC 5V appear at pin 9 of IC103? | |
Check the pins of IC651 and the related circuit. |
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| Check IC103 | ||||
| Does the OSD ouitput signal appear at pins 3, 6 and 8 of IC104? | |
Does the DC 5V appear at pin 14 of IC104? | |
Check IC605 |
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| Check IC104 | ||||
| Does the OSD signal appear at the emitter of QR101, QG101 and QB101? | |
Check QR101, QG101, QB101 | ||
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| Check the video amp and IC102 | ||||
| IC102 IC103 IC104 IC201 IC302 IC605 IC651 |
LM2427T LXC4320 74HC125 ST7271A HS17H KA78R12 7805 |
