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LJ44-00092C

Hello guys, Please i need your assistance with this board [Samsung, LJ44-00092C]. There is a voltage shortage at VG out =15volt and D5v out =5.2v. The current voltage i have here coming out from VG=15volt is 13volt and D5v=5.2volt is 3volt. Every other dc outlets are outputing perfectly fine. I have changed the voltage regulators 7815 for 15volt and Lm2576t which is responsible for 5volt but yet i still get the same

13volt and 3volt out. Can someone tell me what exactly is responsible for this shortage? i'll really welcome your contributions. Thanks guys hope to hear from you sooner. eltron.
Reply to
eltron
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I don't know the board. What is the input voltage for the regulators? I guess it's about 13V and 3V - so no regulation. Is it a switched PS? If switched is the chopper a push-pull arrangement or single ended? Is the transformer hot? Is there extreme ripple on the input voltages of the regulators? Is there a thermistor in series with the line input? Are both regulators on the same rectifier or do they have their own transformer winding, rectifier and capacitor? Last but not least: Do you operate a 230V PS on 120V? Not enough data to suggest a solution.

Kind regards, Eike

--
"The adventures may be mad, but the adventurer must be sane."
                                    - G. K. Chesterton (1908)
Reply to
Eike Lantzsch, ZP6CGE

I agree that the input voltages to those regulators are probably low, and that the most likely cause, is a bad filter cap on a (shared ?) source rail.

Arfa

Reply to
Arfa Daily

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