Troubleshooting a citizen 1212 build

Discussion in 'LED and other Lighting' started by Copernicunny, Mar 13, 2018.

  1.  
    Copernicunny

    Copernicunny Member

    So a little over a month ago I finally decided to start my first grow, and also to build my first led light. After some (not enough, apparently) research, I went for 5x1212, on a HLG-240h-1400b, figuring they should just fit in it. Ordered via kingbrite.

    For the first week or so, everything was fine. Then the problems started. At first, a bit of flickering. Then the potentiometer started acting up - operating basically as a switch, and not well at that. I figured it was all just a bad potentiometer, fuck it, take it off, go full throttle. Took me another day or so to realize I was probably getting less than 100% this way too, likely due to tripping overvolt protection. Removed one cob from the circuit.

    Then the real problems started. Flickering - not the kind of mild rippling I had noticed with the potentiometer, where the light seemed to dip up and down with no real reason, but real on/off flickering. Took me a while to get an order of stuff I needed to rewire the entire light, but it finally arrived yesterday. Redid all the wiring - replaced kingbrite wire with thicker gauge wire, soldered new pot (two, actually) directly to dimming circuit. Not working. Light turns on, but is not as bright as it should be, and dimming doesn't work. Strangely, removing a cob creates the same result - not brighter, the way it did before. It does seem more stable though - no flickering. Anyway, took off the potentiometer, snipped the cable - no noticeable difference in light quantity. It seems like the driver is sending out low current as though its overvolt protection is engaged, even when there's no good reason.

    My thought is there is probably something wrong with the dimming circuit on the driver (or some other part of the driver itself), but also that I'm probably missing something somewhere. I don't have a multimeter but I can get one, and I'm good with a soldering iron but less with electrical theory.

    Help me, Rollitup Led Homies, you're my only hope.
     
  2.  
    diyled

    diyled Well-Known Member

    Have you checked the wattage on a basic wattmeter?

    Ive had a couple customers come to me with this same problem from this supplier. After troubleshooting and getting nowhere, They replaced the cobs with veros and they worked fine.
     
  3.  
    DankaDank

    DankaDank Well-Known Member


    How did you wire the cobs, double check cobs are wired in series, check the ac side is wired correctly. If it is, get a multimeter and test the dc voltage output of the driver. Its the most useful tool when it comes to trouble shooting electronics. Also what is the value on the potentiometer.
     
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  4.  
    Copernicunny

    Copernicunny Member

    Haven't yet, no, but it's definitely not the full 250. That much is clear to the naked eye. I'll put one on the shopping list.

    Yeah I'm really regretting not going with the Veros, which fit on this driver beautifully. Whatever I saved on the 1212s I've already spent on troubleshooting. But at least I'm learning, I guess.
     
    diyled likes this.
  5.  
    Copernicunny

    Copernicunny Member

    They are in series and wired correctly. The AC side is wired correctly too (I think; ground to ground, N to N, L to L). I'll get the multimeter and check.

    The new pots I got are 100k 1/2W, the original is 100k not sure about the other specs.
     
  6.  
    Copernicunny

    Copernicunny Member

    Also I just checked and the light is currently flickering. Not blinking (not turning off, that is), just kind of moving up and down in intensity. Doesn't seem to be on any particular time table.
     
  7.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    just take the pot out to eliminate that as a source of trouble. leave dimming wires open from each other
     
  8.  
    Copernicunny

    Copernicunny Member

    Yeah, I've done this. Right now the cable is just snipped straight, so the wires can't touch, but the last time around I had them separated. Still flickering.
     
  9.  
    welight

    welight Well-Known Member

    Are you lights interconnected with Holders or soldered, flickering is often interconnect related, if your pot is out of circuit and connectivity is good, then the driver is the likely issue
     
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  10.  
    Copernicunny

    Copernicunny Member

    Holders. How would I go about checking this?
     
  11.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    first off is the wire you are using stranded or solid? is it the proper size for the holder spec?

    you can pop the chip out and do a continuity or voltage test to the holder terminal, though intermittent connections can be a real bear to identify
     
  12.  
    Copernicunny

    Copernicunny Member

    Solid wire, 20 AWG, which should be perfect (and sits perfectly snug) with an Ideal holder. I did run some stranded wire through two of the chips for the first week or two though, without tinning them. Could that have something to do with it? Tiny strands of copper left over in the holder causing shorts?

    What are typical problems with holders? I have this sense, now that you guys have brought this up, that when I had it flipped over the other day to rewire it, it didn't flicker when I tested it and it seemed brighter than it does now, but, y'know, my short term memory isn't picture perfect. Could it just be that the holders aren't tight enough? I'll shoot myself if it is.
     
  13.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    easy with ideals as you have a whole second set of pushins and can eject the wires you have
     
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  14.  
    welight

    welight Well-Known Member

    I would dismantle the holders and remove any 'Tiny strands of copper left over in the holder causing shorts?' and try to have the pads as smooth as possible and for good measure before you reassemble wipe the pads with some cleaner in case you left any flux cap on the solder
    Cheers
    Mark
     
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  15.  
    Copernicunny

    Copernicunny Member

    Yeah this seems like a very good idea. By pads do you mean the thermal pads? How would I go about removing them, or smoothing them out? Would I be better off removing them and using a good thermal paste?

    And what do you mean by flux cap on the solder? I didn't solder anything on the chips themselves.
     
  16.  
    Copernicunny

    Copernicunny Member

    Yeah that figures. I wasn't really sure what those were for.

    I think I'll start out by doing a full reassembly. I'd feel pretty dumb spending any more money on this if it's just a matter of doing a better job of mounting them. If that doesn't do the trick, I'll grab a multimeter and keep at it.
     
  17.  
    welight

    welight Well-Known Member

    Yes the COB solder pads if they have some copper wire remains
    Often when you solder a pad, the flux leaves a residue on the solder that can interfere with connectivity, so scrape that off or you a cleaner and light brush so what ever is left on the pad is Solder only
    Cheers
    Mark
     
  18.  
    Copernicunny

    Copernicunny Member

    Well, this is embarassing. I tightened down the screws on all the holders, and now the flickering is gone. Guess KISS is good advice for everything. That said, I think over-voltage protection is still on, and that there may be a problem with the dimming circuit.

    Would a multimeter help me in checking whether that circuit is functional? What would I be checking, and how?
     
    Nutria likes this.
  19.  
    CobKits

    CobKits Well-Known Member Rollitup Advertiser

    imma guess not good contact between spring arm on the ideals and the chips. perhaps chips arent fully clipped into the ideals? look carefully from the top. the ideals are kind of "springy" in that the chip often doesnt make good contact until the screws are fully torqued, sometimes due to that little arm/clip that keeps tension on the side of the chip, it can stick out lower than the chip back and raise the chip up off the heatsink until its all tightened down
     

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