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AC/DC power supply with 19.5V 7.9A issue
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<blockquote data-quote="Geoff1946" data-source="post: 540077" data-attributes="member: 28452"><p>Agreed. The majority of electrical faults, especially intermittent ones, are really mechanical failure. </p><p>Expansion and contraction of metal and other materials, as equipment warms up and cools down causes stresses and eventual microscopic breakage. This can be internal to components or where they are soldered to the printed circuit board.</p><p>It is extremely difficult, even if you have some understanding of electronics, to trace such faults without a circuit diagram and test equipment. Further, switching power supplies are especially difficult because they have protection circuits which monitor for over-voltage/ over-current/ over-temperature, etc, and shut the circuit down.</p><p>Returning to your hope of finding the problem the only thing I can think of to try is to establish if it is temperature related. Warm it gently with a hair dryer. If it then starts working try cooling individual components or joints with a freezer spray. You may just strike lucky but I wouldn't advise you to put your wages on it!</p><p>Above all, be careful ! Even if it isn't working there is mains voltage at one end of the board!</p></blockquote><p></p>
[QUOTE="Geoff1946, post: 540077, member: 28452"] Agreed. The majority of electrical faults, especially intermittent ones, are really mechanical failure. Expansion and contraction of metal and other materials, as equipment warms up and cools down causes stresses and eventual microscopic breakage. This can be internal to components or where they are soldered to the printed circuit board. It is extremely difficult, even if you have some understanding of electronics, to trace such faults without a circuit diagram and test equipment. Further, switching power supplies are especially difficult because they have protection circuits which monitor for over-voltage/ over-current/ over-temperature, etc, and shut the circuit down. Returning to your hope of finding the problem the only thing I can think of to try is to establish if it is temperature related. Warm it gently with a hair dryer. If it then starts working try cooling individual components or joints with a freezer spray. You may just strike lucky but I wouldn't advise you to put your wages on it! Above all, be careful ! Even if it isn't working there is mains voltage at one end of the board! [/QUOTE]
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AC/DC power supply with 19.5V 7.9A issue
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