Repairing 30V 10A DC Power Supply

Thread Starter

narkeleptk

Joined Mar 11, 2019
540
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I bought this ∧ 30V 10A dc supply not too long ago (4 months maybe) as a secondary unit. Hardly used at all and already dead. I have an older similar unit that's always worked great so I am not sure if this one was just a lemon or from a bad batch. At first it seemed to work good, I used it for brief 3/5v loads once in awhile. Til last week I decided to use it more often (mostly 14V 2a loads, nothing fancy or over demanding) Pretty much soon as I started using it full time I started seeing it have issues with dropping power. It would slowly drift from 14V down to 0, Then come back full. This would happen about every 10 minutes. After a few days of monitoring this behavior it finally decided to die completely by blowing the main fuse. Wife told me I should buy a better one so I quickly agree'd, set the dead unit on the junk shelf and found a great deal on this guy:
20210429_204913.jpg



After the replacement supply arrived and got settled in, figured I finally take a look at the busted one. The 2 mosfets are shot for sure, completely shorted. Other then that I'm not seeing anything out of the ordinary. Power supply's are not really my forte tho so I figured I'd see if anybody had any other suggestions on things to look out for while I'm waiting on the replacement mosfets.

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Thread Starter

narkeleptk

Joined Mar 11, 2019
540
Amazing how clean the signal is from the tek power supply vs the cheaper ones I have. A large cap on the output of the generic one helps a lot but still not as clean. I don't really need to do too much where noise interferes but there was a few times awhile back it was hindering me a little and I would always blame my usb pico scope. Rather happy that unit in original post failed and I ended up grabbing a proper supply.

here's a short I did the other day while I was using both.


And....
Since I posted the other one, here is the inside of the tek:
tekps2.jpgtekps.jpg
 
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