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Floodlight Power Adapter Problem Repaired
Last May I posted about repairing LED Floodlight. You can check the link again below:
Today posting is about repairing the LED Floodlight power adapter. Few days ago my friend sent to me another batch of LED Floodlight. This batch had the power adapter outside and it was quite easy to remove from the unit.
The complaint was no power and the first thing I checked was the main fuse and it was open circuit. The power board does not have any burn mark or bulge electrolytic capacitors. As usual, once the main fuse open we have to check on the bridge rectifier.
If you are a newbie I suggest that you check the 4 bridge diodes (1N4007) off board. Since I’m used to check bridge diodes on board, I found two diodes shorted. I don’t just stop at this point, I carried on my inspection to check on power transformer with Blue Ring Tester and found the primary winding to be good. The secondary diode also was tested good.
I concluded that at that very moment only the diodes and the fuse were at fault. Usually when I found one or two bridge diodes shorted I would replace the four of them. If not I’m sure later on (perhaps in few months’ time) the other two bride diodes may give way too.
After replacement of the diodes I connected a 100 Watt bulb across the fuse solder points. I then used my faithful Greenlee Digital Multimeter and set to Volt range and placed the probes on the output terminal. When the power was applied, the bulb did not even light up at all (this indicates there was no short circuit) and I could see the voltage result from my multimeter.
With this test, now I can remove the bulb and put in the main fuse without worrying that the power section or the semiconductors would blow again. From the photo you could see the output voltage measured 26.39 volt and the LED Floodlight happily lighted.
Just in case if the bulb is extremely bright and would not go dim then I have no choice other than to direct replace the power IC and retest.
After done this repair work I began to check on another similar power adapter and found that there was only a shorted secondary diode. The part number was SR5150 rated at 5 ampere 150 volt as seen from the photo below.
Conclusion- This is a small power adapter thus it is not tough to repair it. Just follow some simple troubleshooting procedure and I believe you can have the same success like me. If you want to be good in power supply repair you can check out my best seller power supply repair ebook HERE.
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