Help me fix my Taotronic 120wt please

Bovine · Nov 28, 2012

So I bought 3 of these units off craigslist about a year ago for $300. The guy i bought them from said he only used them about a year. I have used the 3 units now for 8 months. In the last 2 months i have had problems with all 3 units. First unit white and blue went out. Second unit white went out. third unit white went out along with fans... So i have put my 400w mh back on the 180. boy i liked the look of the leds much better. anywhoo i realize they offer repairs, Ive called customer service 3 times in the last 2 weeks and left messages..no response.
So i have opened up one of the units to see how intense the insides look. Not to difficult i think i might be able to do the repairs myself with a little bit of help/knowledge from you guys.
Once i opened the unit i noticed moisture/corrosion. Could be from where i had it mounted in my 90 gallon canopy and it just didn't have enough fresh air to breathe. With evap at a gallon a day on the 90 im sure it did a toll on these units. My wrecklessness i know, but you live and learn.
first picture is a full shot of the unit once opened

Bovine · Nov 28, 2012

Here is a close up of the burnt piece

Bovine · Nov 28, 2012

Sorry for the double pic there..
anyways here is a close up of the same piece that ISNT burnt up

Bovine · Nov 28, 2012

The part number on the relay/resistor/chip thing is GBU8K..
im no electronics engineer. With that being said i need some help. I have pretty good common sense/general knowledge to fix these things i think.
i found this data sheet when i put that part number into google
http://www.datasheetcatalog.org/datasheet/wte/GBU8A.pdf
could someone tell me excatly what this part does?
Also where can i pic a new one up? Radio shack you think?
Please dont judge me by the inside of my units

Thank r2r friends

Bovine · Nov 28, 2012

i think its a

sounds like a cheap fix

ReefLEDLights · Nov 28, 2012

LED Fixtures are rather simple.

-LED String
-Driver
-Optics
-Heatsink & Thermal Management.

A majority of Chinese Fixtures were designed to last one day after the warranty expires and even then I would not want to be an importer of these now. Simple economics selling thousands and saving a couple of cents on each part adds up... As long as the Fixture lasts longer than the warranty.

The driver is their common generic non specific one. We have seen problems with these which is a reason we do not import fixtures from China.

There are a couple of variations Vf range and Current. Your LEDs on the Circuit Board should still be good unless you see corrosion on the board itself.

I would simply salvage the Circuit Board replace the fans with a quieter longer lasting one and re wire with the right Mean Well or Inventronics Driver. The LEDs, even if they are the less efficient three watt Bridgelux, will be more efficient than MH If the LEDs are one watt I would start from scratch and look into a DIY or AI.

Post the number of LEDs in series and type or Serial number of the current driver or Voltage and Current output of the driver... With this anyone can give you a quick driver recommendation.

Bill

Bovine · Nov 29, 2012

Hey thanks Bill for the quick response!
Yes the LED circuit board looks fine, only the bridge rectifier seems do be damaged. But im sure that another component failed, to cause the GBU8K part to melt.
I would not mind buying a driver. The unit seems to have a driver for the blues and a driver for the white's. This particular module proclaims to have 3w Cree LED. There are 30 white led's. And 25 blue's.
The driver has a sticker on it that says
80-130v 520ma
B W
I could invest a little into them and make them better then the where before(longterm) and i hope to be able to do so. I sure would love to go out and buy some new top of the line stuff.. its just not possible at this time.
THANKS AGAIN
Beau

averageguysaquatics · Nov 29, 2012

IMO go with another fixture. I have seen this happen alot. The issue I see you having in the future is once you get this fixed something else will go out. Ive seen the blues go out , then the fans, get them fixed then the whites quit.

ReefLEDLights · Nov 30, 2012

Bovine said:
Hey thanks Bill for the quick response!
Yes the LED circuit board looks fine, only the bridge rectifier seems do be damaged. But im sure that another component failed, to cause the GBU8K part to melt.
I would not mind buying a driver. The unit seems to have a driver for the blues and a driver for the white's. This particular module proclaims to have 3w Cree LED. There are 30 white led's. And 25 blue's.
The driver has a sticker on it that says
80-130v 520ma
B W
I could invest a little into them and make them better then the where before(longterm) and i hope to be able to do so. I sure would love to go out and buy some new top of the line stuff.. its just not possible at this time.
THANKS AGAIN
Beau

Beau

Cree 3 watt LEDs are normally driven at 700mA or 2 watts. At 350mA they are thermally stable with limited thermal management.

These guys chose the middle road and tossed on some fans. This is common in Chinese Fixtures as a quality heatsink is expensive.

This driver should work for you http://www.inventronics-co.com/uploads/2012_10_2517340.pdf

The 450mA for sure or maybe the 700mA. This driver is also dimmable.

Bill

saratj1 · Dec 16, 2012

If you'd like to get rid of them cheap let me know. Lol

Bovine · Dec 18, 2012

what do you consider cheap? If fixing them is going to be that easy for you, share your knowlage with a fellow reefer.

I checked out the drivers that was posted earlier in the thread, they seem to be running $80-90 for one driver if im not mistaken... Im on the fence of whether or not i want to start buying that exspensive of parts for such cheaply built units, like others have stated before in the thread being a waste of time...I just feel like im buying lexus parts and installing them in a kia. But with enough lexus parts there wont be any kia parts left... idk they are still just sitting here....

ReefLEDLights · Dec 18, 2012

Bovine

You have a very good point.

There are not many quality Cree fixtures cheap.

That said we tested one Quality Cree XT-E Fixture against one of the better Chinese Bridglux fixtures. The Cree gave us 460 PAR @ 24" using only 118 watts. The Chinese Fixture was 390 PAR @ 139 Watts

3.89 PAR per Watt v 2.80 PAR Per Watt or 39% more efficient. The Cheaper Chinese fixtures without optics gave us only 210 PAR with 138 watts. These readings were uncorrected.

In the Long Run with electricity only going up it may be less expensive to spend a little more on a quality Cree Fixture.

Bill

saratj1 · Dec 18, 2012

Bovine said:
what do you consider cheap? If fixing them is going to be that easy for you, share your knowlage with a fellow reefer. I checked out the drivers that was posted earlier in the thread, they seem to be running $80-90 for one driver if im not mistaken... Im on the fence of whether or not i want to start buying that exspensive of parts for such cheaply built units, like others have stated before in the thread being a waste of time...I just feel like im buying lexus parts and installing them in a kia. But with enough lexus parts there wont be any kia parts left... idk they are still just sitting here....

Just figure out how they are wired how many individual LEDs are on a string.. Then look for bridgelux 3w LEDs forward voltage is. Multiply that number by how many are wired together in series. Then look for the correct amperage, probably around 500mA. To run them at 2w.
So for maths sake lets say they have 10 LEDs per series. The voltage forward is 3.3v,
You'd want a driver that has an out put of 33v, @500mA, or 1A to run two strings on it.
This is an example, but should be close to what you want to do.