EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: cinetron on March 23, 2017, 07:09:32 am
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I have a dead Extech 382275 bench top PSU and after removing the board discovered it has a couple of other names by other manufacturers. The board inside says HCS-3400 Power Board by Manson . Looking on-line I discovered it is also sold as a Maas HCS-3402. I found a video in German that discusses repairing one of these supplies but I can't follow it, and turning on English subtitles just makes it quite hilarious as the translation is so bad. Anyway at one point the person in the video I believe discusses the problem which I think are blown diodes. I was wondering if anyone who speaks German could take a quick look around the 15:30 mark and let me know if this is indeed the issue. When I measure the same diodes in circuit they appear shorted but not sure if they are or it is just surrounding circuitry that makes them appear that way. I have no schematics and it is difficult to trace the circuit? Anyway if there is anyone who could help I would sure appreciate it. I really don't want this supply to end up being unusable. Here is the link to the video. https://www.youtube.com/watch?v=C1zg-OhT6r4 (https://www.youtube.com/watch?v=C1zg-OhT6r4)
Thanks!!
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He said, there's 2 diodes in one case, as schema shows.
He tested by using a multimeter in diode test mode.
What is self-explainig...
Do you have more questions?
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And he said that he removed the diodes prior to testing them.
The left one was blown and got replaced.
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Around 20:00 both mosfets fail after he replaced the diode. He doesn't know if this was related to the shorted diodes, but could be.
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This forum is amazingly international! :clap:
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Wow thanks so much for the help with this. I was at a loss to know what he was saying. Hopefully this will lead to a revived power supply :)
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Hi Cinetron,
i have the same (Manson branded) device here with a blown current shunt resistor.
Is there a value printed on it?
If not, are you able to measure the value for me?
Manson is the original manufacturer. They do not provide schematics :(