I fried my fish tank LED light

Thread Starter

Crockett

Joined Jul 3, 2017
5
Hey guys, I'm new here and pretty much a noob regarding electronics. I know how basic components work, own 2 good multimeter, an oscilloscope, an adjustable power supply and a Weller SMD solder station.

I got into a new hobby recently, which is aqua-scaping. Unfortunately I managed to mix up the 12 V power supplies of my fish tank LED light bar and the Bluetooth module from the same company. Problem is that they have reversed polarity at the plug, hence I shot both items.

Now, I really want to fix this myself, with suggestions and help from you guys. I contacted the manufacturer but they didn't reply.

The LED light works with and without the Bluetooth controller. That's why I started pulling the light apart. The light consist of 2 boards: one long board with all the LEDs and very few components, and a short board that accepts the 2 wires from the 12 V power supply and a USB cable coming from the Blutooth module. The Bluetooth module controls brightness and color channels only.

I took a high res photo of the short board only, because I believe (and hope) that the only components being shot are on this part.

Full size image (7 MB): https://s11.postimg.org/h3fv8mo35/DSC00777.jpg



So where and how do I get started in trouble shooting this board?
 

dl324

Joined Mar 30, 2015
11,855
Welcome to AAC!
So where and how do I get started in trouble shooting this board?
It would be helpful if you posted a schematic. If not available, trace the circuitry and make one.

What is the part number on the 5 pin device near the power leads? It looks like it's scorched.
 

Thread Starter

Crockett

Joined Jul 3, 2017
5
Welcome to AAC!
It would be helpful if you posted a schematic. If not available, trace the circuitry and make one.

What is the part number on the 5 pin device near the power leads? It looks like it's scorched.

Hey Dennis, thank you so much for looking into this.

I do not have the schematics and I'm sure the manufacturer won't provide them. I'd draw them as best as I could but they covered most of the board with some form of resin which makes it really hard to see and read the traces / components. Is there any way to remove this hard film?

I was able to take another photo of the 5 legged IC, that alone took me 20 min and several attempts.



The last digit sometimes looks like a 8 or 6 but I'm 90% sure it reads L333.

I tried to googled it but didn't find anything 100% conclusive. Is it a Switching Voltage Regulator?

http://www.mouser.com/Semiconductors/Power-Management-ICs/_/N-wnwh?Keyword=L333&FS=True

Is there any type of database with all components?
 

dl324

Joined Mar 30, 2015
11,855
The last digit sometimes looks like a 8 or 6 but I'm 90% sure it reads L333.

I tried to googled it but didn't find anything 100%. Is it a Switching Voltage Regulator?
Looks like it could be a 3.3V regulator:
upload_2017-7-3_20-28-38.png

Is there a type of database with all components?
There are some SMD marking references. I couldn't locate mine, so I googled for "SMD L333"

Apply power and measure the voltage between pins 5 and 2. You should get 3.3V.
upload_2017-7-3_20-30-25.png
 

Thread Starter

Crockett

Joined Jul 3, 2017
5
What are the part numbers on the other semiconductors? Can you trace how one sub circuit is connected?
The part numbers on the main chip of each sub circuit are:

MIC
3203YM
1613

I have found this information:High Brightness LED driver MIC3203YM.

Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/MIC3203YM Evaluation Board User Guide.pdf

I guess those 3 sub circuits are for each RGB color channel, which can be adjusted if the Blutooth module is hooked up. If not, all channels are on and on full brightness, rendering the light output bright white.

Is it possible to test this chip based on the datasheet alone?

I'm still reading up on how to draw schematics. I also wonder if this board has any sandwiched traces that I won't be able to see.
 

dl324

Joined Mar 30, 2015
11,855
I'm still reading up on how to draw schematics. I also wonder if this board has any sandwiched traces that I won't be able to see.
Check all of the vias to see if they have a trace on both sides of the board. If they don't, the board has inner layers. You're out of luck if it has blind vias unless you can hold the board up to a light and see if there are any inner layers.

Looks like you'll need to connect some LEDs to see if the rest of the circuit is functioning.
 

Thread Starter

Crockett

Joined Jul 3, 2017
5
Check all of the vias to see if they have a trace on both sides of the board. If they don't, the board has inner layers. You're out of luck if it has blind vias unless you can hold the board up to a light and see if there are any inner layers.

Looks like you'll need to connect some LEDs to see if the rest of the circuit is functioning.

Ok, this is now really embarrassing.

The manufacturer called and we figured it out. The LED light needs a 24 V power supply and I grabbed one with 12 V. With other words, the LED light is not fried at all, the 12 V just didn't cut it. Just hooked up the matching supply and all is working.

I mixed up the power supplies, because the aquarium filter uses the same 24 V power supplied and that's where the LED supply ended up being, and the 12 V must be from the skimmer or something.

I'll mark all power supplies from now on! I guess I'm getting old. :(

What a joke.

Thank you Dennis for looking into this, I really appreciate it. I'll be back soon with my next screw-up. lol
 

dl324

Joined Mar 30, 2015
11,855
Ok, this is now really embarrassing.
Glad you got it straightened out.

There's always going to be a problem with standardized connectors. There was a recent thread about a guy's Wife using adapters so she could connect his 120VAC battery charger to a 240VAC outlet. His Wife survived, the charger didn't...
 
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