Cheap Chinese Blurples: The Naked Truth; a review, teardown, failure analysis, repair, and upgrade

TrippleDip

Well-Known Member
The Review
These lights right now retail for 80 cad. Would I get them knowing what I know now? No, mostly because of spectrum. These lights put out 180W at the wall and that is pretty good for 80 bucks. Should someone starting out consider them as an option? Why not, they will grow decent bud and are one third the cost of samsung f series strips per watt. I got two years of use out of them (the warranty period) but eventually a third stopped lighting up (I blame a fan failure where they were running for 12h at 45*C). Naturally I popped them open.


The Teardown
Well, idk what I expected to find inside, but it's just three 60-90V 700mA drivers each attached to a string of either 33 or 34 leds on an aluminum board. There's also small heatsink and two fans. Oh yeah, each of the leds is in parallel with a small zener diode.

1.jpg


Failure Analysis
At first I thought multiple leds had burnt out, but a quick trio through the boards (two of them) showed that each had exactly one led fail, and not only that, had every single blue led self immolate.

2.jpg

Believe it or not, the blackened led is working perfectly, and the yellow (warm white) led in front is the one that failed. Note the burning on the zener diode - the led failed open and the zener passed current until it burnt.

I don't understand the zener diodes. I think they are either added as a selling point?!? (possible?) or as a measure to keep a light with a failed led running past the warranty date (most likely). There is no way they are specd to dissipate that much current continuously, or as a easy way to tell which led failed on their lights in the event of a return (least likely).

It is interesting that both diodes that failed were almost in the same position. The reason is that the boards have a hot spot created by the wiring and drivers blocking air movement in one corner. Their lights lifespans could be significantly improved by simply mounting the drivers outside of the case or adding an extra half inch of height.


The Repair & Upgrade
Well a light application of force through wire cutters popped the leds right of the board. I ended up soldering two new ones then switched to thermal conductive epoxy for the rest.

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I replaced many of the red leds with white ones. The light went from 180W with 55W of blue and white to 190W with 75W of white. The rest of the watts are mostly red with some orange and 10W of uv and ir.

Possible future upgrades I am considering is putting the board in the oven, wiping it clean and replacing all the leds with high efficiency 1W ones, thus liberating two of the three drivers for future projects. Should I replace even more of the red leds with white? Only 6 or 9 can be changed without removing some because of the driver voltage.

Hope this finds any interested parties, just want to let you know what you are buying and/or how to fix it if you can score or already have a dead one.
 

Boatguy

Well-Known Member
Hope this finds any interested parties, just want to let you know what you are buying and/or how to fix it if you can score or already have a dead one.
You would be better off spending your time on something else. Even the light i built in 2014 was more efficient and at least passively cooled.
 

TrippleDip

Well-Known Member
You would be better off spending your time on something else.
Than repairing something I already have for pennies? Making it better even. Besides, maybe somebody else will be inclined to fix their light and could use the tips like popping the leds off the aluminum board with wirecutters (see how clean they came off) and using thermal epoxy because heating up the aluminum board is a pita.

PS: even if you save 20% of your energy (not really possible, maybe 5-10% max), then you are saving about 5c a day on powering a 180W light for 12h. Less than $20 a year provided you grow year round, which anyone growing for personal use is unlikely to do.


Do you have a link to the light or at least a model name you can share?
I'm not endorsing any particular light. Bet they are all pretty similar - commercial drivers and leds on an aluminum board. They're not even all that good, but they're cheap and that may matter to someone trying out a hobby without getting too invested - the exact reason I chose blurple over more expensive panels.

Now that I know I like growing I will slowly upgrade what I think needs it. Not buying a bunch of stuff right off the get go would help a lot of people because they will see what they need when they need it instead of reaching for the tools they have but that might not be the right ones for them, also because they will not be replacing expensive stuff with more expensive stuff.
 

10WeekFlushBro

Well-Known Member
Most posts here are absolute entry level. Now somebody comes with an informative thread and gets told to do something else. I think you shared some interesting info that shows how awful these "diode coffins" as I call them are.
 
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