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proview 770m dead setSeptember 21 2004 at 4:18 AM
No score for this post | rg (no login) |
| dead set.replaced shorted fast diode at secondary of power switching transformer. still dead set with ticking sound. flyback ring test ok. pin 8 of smps ic alternately dropping 5vdc-0vdc. supply of smps ic going negative alternately from very low volts dc in synch with the pin 8 variations
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Richard B
(no login) | Re: proview 770m dead setNo score for this post | September 21 2004, 4:31 AM |
You did not state the PCB reference of the diode you replaced and what you replaced it with.
This would help if we have any notes or schematics.
The condition you describe sounds as if you still have a heavy load.
Rich
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rg
(no login) | dead proview 770mNo score for this post | September 21 2004, 5:09 AM |
i dont have schematic i'll give you the index number later as it was my colleague who replaced it. meanwhile the smsps fet burnt.that is q502 can you give me it's number as the number is unreadable. thanks
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Richard B
(no login) | Re: dead proview 770mNo score for this post | September 21 2004, 6:42 AM |
Q502 can be,
IRF IBC40G
2SK2645
FS10KM-12
Rich
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rg
(no login) | proview 770m dead setNo score for this post | September 22 2004, 1:50 AM |
the shrted diode's index number on the PCB is D507 it is supplying 80VDC to the video board at the CRT base.
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Richard B
(no login) | Re: proview 770m dead setNo score for this post | September 22 2004, 4:26 AM |
This may have died due to PSU output voltages being too high.
The result is that your video output IC maybe S/C.
Check C521.
Rich
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