Fan controller killed two 12v 2A DC adapters!

Thread Starter

Bassquake

Joined Feb 16, 2018
58
I was using this 12v fan controller (see photos) to control an led strip. After about 6 hours, I noticed it stopped working (probably not enough current and something blew on both the controller and psu).

Used a multimeter to check psu and had no voltage coming out at all.

Tried another working psu, turned the fan controller and.. nothing. Unhooked psu and measured power on psu and now thats reading 0v!

Something on the fan controller killed both psus. I'm going to replace the LM317T Regulator on it to see if that fixes controller, but Id like to repair the psus as well.

What is the most likely component on the psus to die in both circumstances??

Have attached images of both psus and the fan controller. (One has an led. Ignore the cut wires on one of the psus, they were already like that before I opened it up.)

Let me know if need more details. Thanks.
 

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BobTPH

Joined Jun 5, 2013
4,950
Your adapters rated at 2A may not be able to actually provide 2A continuously. You should always leave a little headroom.

Did the controller board get hot? Maybe it has a problem.

Do you have a multimeter and a power supply that can supply 3A or more? If so, measure the actual current.

Bob
 

Thread Starter

Bassquake

Joined Feb 16, 2018
58
I will get a 3A one. But for now the issue is the psu units are both outputting 0v. Id like to use them for other (less draining!) projects rather than be landfill.
 

AlbertHall

Joined Jun 4, 2014
12,028
I will get a 3A one. But for now the issue is the psu units are both outputting 0v. Id like to use them for other (less draining!) projects rather than be landfill.
Have you tried leaving them off for at least a minute, and then trying them again with no load?
 

Rod777

Joined Aug 24, 2019
6
Just looking at the underside of the board, the power diodes look to be dry jointed. The solder isn't as bright as it should be also the solder doesn't appear to be contacting the leads as it should. These might be arcing across the solder and causing all sorts of spikes. This is just an observation.
 

Thread Starter

Bassquake

Joined Feb 16, 2018
58
Just looking at the underside of the board, the power diodes look to be dry jointed. The solder isn't as bright as it should be also the solder doesn't appear to be contacting the leads as it should. These might be arcing across the solder and causing all sorts of spikes. This is just an observation.
I can try reflowing the solder but it doesnt explain why 2 power adapters died. The pictures I attached in this post are of both.

I need to know which component would most likely be the blown component in these power adapters?

Also, what shall I use on the fan controller to stop it happening again? A fuse or diode on the positive side of the cable that plugs to power adapter?
 

sirkit

Joined Aug 24, 2008
3
I can try reflowing the solder but it doesnt explain why 2 power adapters died. The pictures I attached in this post are of both.

I need to know which component would most likely be the blown component in these power adapters?

Also, what shall I use on the fan controller to stop it happening again? A fuse or diode on the positive side of the cable that plugs to power adapter?
 

Thread Starter

Bassquake

Joined Feb 16, 2018
58
LM317T is a 1.5Amp regulator, probably blown if your circuit is drawing 2Amps
Yeh, replaced the LM317T on the fan controller and its working now.

Just need to know what to replace on the PSUs now! I'm awaiting delivery on some 5L0380R IC for one of the PSUs which might sort it.
 
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