Bad diodes on QB. Advice?

Discussion in 'Lighting' started by GrowGlow, Jun 7, 2019.

  1. I bought all my QB lights from Meijiu. My latest 301B board had 1 diode not light up and I was refunded the price of only the board. They originally offered a mere 20 buck.

    Few weeks later, my old 561C board has 1 dead diode and another 15 in a very dimmed state. Luckily…it is a few weeks from being a year from date of purchase. I have sent feedback and will wait for a reply on Monday. Before that, I shall not comment on their after sales service. If I do not get a reasonable compensation for this, I will raise hell lol!

    Now for my real issue needing advice. Anyone knows how to fix/ replace bad diodes with minimal equipment?
    561C
    [​IMG]
    301B
    [​IMG]
     
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  2. The old diode will have to be super carefully unsoldered and removed.. then the new diode will have to be placed in the correct positioning of polarity then ohh so carefully soldered into position.. all this will have to be done with the thought u can possibly burn the board with the solder gun.. plz be careful..

    (If u feel u can do it.. im wit u everystep of the way)..

    Theirs videos online that show how to actually remove and replace diodes wit super clarity and info..




    Flower tent Vegging outside the flower tent
     
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  3. Looks like I'm gonna have to abandon the thought cos I can't do electronics to save my life lol.

    Really disappointed in Meijiu quality. Hope they give me a good reply come Monday. Too many of us buy from them for them to not stand behind their product! Dammit!
     
  4. This is the first complaint I’ve seen about replica QB’s. Which sometimes it just takes time for equipment to be tested long enough to have issues. But this is why I stayed away from ordering them. Not knocking you or your decision I think this kind of stuff is important to see for when people are wrestling with buying true HLG products vs the replicas purely for the data on longevity. Sorry to hear you’re having issues!! Hopefully you get it resolved in a manner you’re happy with because in the end that’s all that matters! I’d be curious to see if others have had similar issues....


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  5. Shit happens and since I know I used them properly, I attribute it to bad luck. Any company could have defective products.

    As you can see, I'm trying to give them the benefit of the doubt. Since they did refund me $125 for the 301b board with one bad diode. I call that standing behind their product. But that was a few month old board just used for couple weeks max.

    Few weeks apart, now this is an older 561C board with many diodes going dim. I originally thought it was over a year but checked records and its still within a year. Its a public holiday in China so I'll wait till Monday. If they stand by their product, I'll maintain support. Otherwise, will caution everyone else to not buy from them.
     
  6. Fair enough!! I feel like you’re definitely justified across the board not that my opinion matters lol. Just you’re definitely going at this unbiased and forming your opinions based on results. So I’m with ya! Also, it really makes it hard to discredit or air away from companies that will make up for things that go wrong!! I just had the same situation bought some beans was supposed to get 6 freebies only received 3. My opinion of them hinges on their willingness to fix it. Messaged them they took full ownership of the fuck up and sent me the original 6 so I ended up with 9 freebies. They get a 5 star rating from me!
     
  7. I had a small QB128 from Meiju with a bad plug for the power on the board. I ended up using a binder clip to fix it. They refunded me the whole price of the board/driver but it did take a little bit of negotiation. They wanted to give me 20 bucks at first too. I think in their head, Im going to take the 20 bucks, buy a part and fix the board myself..... After I explained to them that it would cost me the same amount as the board itself to have a local shop fix it since I don't have the tools to do so, they sent me the refund. Ive been rocking 2 of their HLG65 replicas and one of the 550V2S since February on 24/7 light and haven't had any issues. Binder clip is still holding lol!
     
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  8. Lets see if they will honor my second, older board? They gotta know we are united!
     
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  9. I have fixed them before, you have to break off the bad led and solder on a resistor of the right size. Its really hard to acually solder on a led. The plastic melts and contaminates the solder.

    On the board with a dim string, you have a bad solder joint. Soon the string will fail; but the leds should be just fine as it likely eill be 1 led causing you grief.
     
  10. I have fixed them before, you have to break off the bad led and solder on a resistor of the right size. Its really hard to acually solder on a led. The plastic melts and contaminates the solder.

    On the board with a dim string, you have a bad solder joint. Soon the string will fail; but the leds should be just fine as it likely eill be 1 led causing you grief.
     
  11. Bad solder joint meaning a quality issue? Would it take that long to manifest itself? Not sure I even know what a solder joint is? Lol

    I definitely don't have the skills, tools or balls to repair them. Would really like to know what caused them if you'd know?
     
  12. Here is a better way to describe the issue or potential issue; a COLD solder joint. It basicly means the led chip didnt get soldered to the board properly and isnt making good contact. I dont really know if it leads to a corrosion issue or somthing else. Issues can manifest anytime. I have had issues with HLGs products also.

    In regards to a quality issue it could be they use cheap solder paste. I cant say.

    I wouldn't be too worried about hurting the board by working on it, I have literally cut boards in half and did a little rewiring and they work.

    Another has done this too and the pictures look sweet.

    They appear fragile but when it comes to it they double as a frisbee. (Not serious on that one)
     
  13. Sounds to me like its most likely a manufacturing issue then? I was considering if I may have broken it but after hanging it up, I've done nothing to it. One day it was good and another it isn't. Can't think of a way i could have messed up the solder joint. Still don't really know what that is tbh.

    I really don't have any tools with me to perform the repair, even if i grew a pair overnight!

    I don't think they will replace the board cos they chose to refund the last time. No reason they won't at least refund this time round. But you never know! I will continue using the board cos its probably a couple Watts missing which should not matter.
     

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