Diagnosing LED fault

ph123uk · Jan 17, 2019

Hey all,

Bought a new light with the intention of using it on my display due to having a controller sunrise etc etc, sadly its broken. It is a 4 channel DSunY light - the controller is also cream crackered but I hold hope that I can use reef pi to control this eventually

One of the strings (4th channel) is down completely see attached pics

As you can see something has "blown" looks like a ceramic SMD cap? (C25)

Any way I can test to see what the problem is ... I.e. just the cap? Or test the LEDs

I do have a multimeter here so any help would be great

Is there any way I can change that little cap, any way of finding out its value?

Any basic information you can give me would be great

sbash · Jan 17, 2019

The first thing I do in these situation is set my multimeter to resistance mode at the lowest ohm (2M?). It pushes just enough power to faintly light a single LED. Go through each LED one by one until you find the dead one...

In the second picture, your shadow is covering part of the board that look burnt? Can you tell what any of the marking are on the components?

Did you check YouTube for folks who are modding or repairing this fixture?

ph123uk · Jan 17, 2019

Sadly nobody has a video

The Leds themselves appear to be fine, my diode setting gives a reading of 0.201 to 0.204 on all the LEDS it's sadly not capable of lighting them.

Running a continuity test on the driver chip pins to each of the 4 components to the right of it gives me a positive except for on the bottom of c25 - the burned one