Led testing help!

[setsail4mexico]

I have an Aquatic Life 54w light. Has 54 1w LEDs in 3 strings of 18. The first string has 3 LEDs that light up (all blue) the other two strings are working fine. The first string has a voltage of 15.59 volts and the two working strings show a 19.2 volts. Any help on how to test what is going on in the first string would help.

 

[Safir]

Are you able to work out the wiring details? any markings on any drivers in it?

there must be some combination of strings of lights wired in parallel, Knowing any details would help immenely in troubleshooting.

Also, would it be possible to get a picture with the light off? I am not personally familiar with this particular light and am having trouble finding detailed pictures of the LEDs

 

[setsail4mexico]

Here are some more pics... There are two drivers, both meanwell. The lpc-60-1050 is powering the two strings in parallel that are working... The lpc-35-1050 is the one powering the string that is having issues.

 

[setsail4mexico]

 

[Safir]

Looks like you have 3 strings of 6 LEDs.

You should be able to verify this by following the traces on the board, there will be three sets of 6 LEDs wired + to - with the beginning and end of each set connected to the + and - busses along the top and bottom of the board.

The fact that only three LEDS are lit is perplexing - was this light working before and recently failed? There may be multiple failures we are dealing with here.

I would measure resistance across the + and - busses - so from the DC+ on one end to the DC+ on the other end, and the same for DC-. That way you can determine if either bus is damaged.

Then I would measure resistance across each diode individually, looking for anomalies.

edit: in case it is not obvious, test resistance with the light unplugged

 

[Snookster]

I've found that a single bad led can take the series down. Test each one with your test (if you have one) and replace the bad one if that's the case. I had a surge last year from a storm that ended up shortening the lifespan of each one. They died one by one, after replacing the previous one of course.

 

[setsail4mexico]

Thanks for your help. I went through and tested each led with my fluke multimeter so they would light up from the power from the multimeter and found that every led that is out is dead. I also found out aquatic life warranties their light for life (labor only- you pay for parts and shipping) so I think I'm just going to send it back to them and let them take care of it. This was my five light... I'm now using an old pc as a replacement until that happens.

 

[CrazyEyes]

Wow, are those the factory drivers?

 

[setsail4mexico]

Wow, are those the factory drivers?

Yes... Didn't even know they had meanwell drivers until I just opened it! And with the original price of this light at over $500 they best warranty it for life! I thankfully didn't pay that since I got it second hand!!!