LEDgardener

so I bought a 800 board from meijiu with a meanwell hlg-320h-48b driver and it appears that the light was damaged during shipping. one of the rows doesn't light up when turned on.

im new to electrical type stuff but I am a quick learner. I have a multimeter. I believe the board is 50 series of 16 LEDs wired in parallel. so its probably just one led thats making the row not work. what can I do to diagnose and possibly repair this board?

Well worth a look to see if it can be repaired (-:

Firstly I'd recommend a thorough visual inspection.

You say believed damaged in transit.. Can you see anything bent, dented, chipped, knocked - concentrate you deductions from there and beyond.. Eye up all the solder joints, other components and LEDs and look for anything suspicious like cracks or something obvious - you'd be surprised what a good stare can reveal and it's advised to try and intimidate the patient a bit before beginning anything physical.

OR

Just get in there with your multimeter - Whilst powered on you can follow from parts of the circuit that DOES gives you some DC volt readings like where the power connector joins. Just gotta find a bit that does work and then test through until there's a bit that does't. There's lots of circuit runs that do work so you should be able to compare probings around and in the dead area with known good readings.

Stick 1 test lead to a + or - somewhere and the other is free to waggle around and be nosy

Trying to think if some continuity measurements might give some insight... If there's a break/problem somewhere it should give a high or infinite resistance reading. Maybe hear a beep or 2 here and there - (still amazes me that does. Used to have to wire up a bulb and a battery).

Check resistors with the Ohms setting too. Often the value is written on them.

Any of these tests might find the problem.

I'm no expert but that's what I'd do. If you do need to solder anything try to get in there with an iron not a hot air torch - both should do it but the hot air can do easy damage if left heating too long. Also the LEDs datasheets will give temperature tolerances and recommended max values for soldering and storage and other stuff! Soldering small things can be easier than you'd think. And besides you might not make it worse and end up fixing it with a result.
Good luck

ive discovered that leds 1 and 2 in the series are faulty, if I bridge over them the rest of the series lights up. meijiu is going to pay for replacement leds and repairs.

meijiu is telling me that the leds they used on my board are AZ V4 S6. now I understand that this means the the flux bin was S6 and the vf bin was AZ. the V4 is the part that is confusing me. I've reached the limit of my understanding of leds and the language barrier between meijiu and I isn't helping.

I was looking at these leds from digikey and they seem to be the same flux bin(s6)and the same vf bin. Samsung's data sheet lists AZ fv bin as 2.7-2.8 and digikey lists these ase 2.75 volts.
so I guess my questions are:

1)what does the V4 refer to?

2)will the leds that I selected from digikey be appropriate replacements

How will these be repaired? I’d just ask them for a replacement board.

LEDG wrote: ↑

Wed Mar 28, 2018 6:37 pm

How will these be repaired? I’d just ask them for a replacement board.

I talked to a local computer repair shop and they said they could solder the diodes. its possible to do that type of soldering by hand right?

I did take your advice however. im just gonna ask for a new one.