Any LED DIY Junkies in here. Need Help.

[mehrific]

Noticed in last grow that a section of this LED panel went bad. Want to fix it myself to put it back into the lineup. No rush on this, i have plenty of lighting equipment. I want to order some parts to fix this issue but dont know what has gotten damaged. Check out image and tell me what I can do. If you fellas
need any other info let me know. Thanks in Advance. -Mehraculous

 

[RainerRocks]

Well it looks like you have sections in that panel divided equally. So my guess is you have 4 drivers also.

Either the driver is bad or the LED's in that series have gone kaput for one reason or another.Or loose wire connection.

Only way to find out is to open it up (disconnect power first ) and test each LED with some AA batteries to find out if it's the LED's .

This is what I used to test my LED's ( Rapid sent it with my order for free ) . Just touch the + and - leads to the + and - on LED. Or build your own tester.
http://www.rapidled.com/led-testers/

PS: Seems these type of threads of chinese lights failing are becoming common. They use the cheapest parts so don't expect them to last long. When
I was emailing chinese LED companies and asking about what type of Drivers..heatsink specs and wire gauge etc I never did get an answer.

 

[tekdc911]

is it a zener unit ? if so then its the pack if not then maybe a led if there daisy chained
well then the flicker is a bit strange if you bump it "gently" does it flicker or does it happen in a pattern like the ballast / power pack is warming up then firing then shuts down
i would start with the power pack
unplug it and open it up wiggle the connections could possibly be a bad soldier connect or connector if it is shock sensitive and comes on when you bump the unit when its plugged in

 

[RainerRocks]

is it a zener unit ? if so then its the pack if not then maybe a led if there daisy chained
well then the flicker is a bit strange if you bump it "gently" does it flicker or does it happen in a pattern like the ballast / power pack is warming up then firing then shuts down
i would start with the power pack
unplug it and open it up wiggle the connections could possibly be a bad soldier connect or connector if it is shock sensitive and comes on when you bump the unit when its plugged in

I think he said it's dead..no mention of flickering . But good idea to gently tap the unit in that corner to see if it's a loose connection.

Edit: His post didn't say anything about flicker but when you click on the picture for a bigger view he does say they flicker.

 

[FranJan]

Have you opened it up yet? That's going to help everyone tell what's going on. Plus you can swap drivers to see if it's a bad driver or not. I hope it's not a Blackstar type of panel with bad diodes. You gotta have patience to fix those.

 

[mehrific]

is it a zener unit ? if so then its the pack if not then maybe a led if there daisy chained
well then the flicker is a bit strange if you bump it "gently" does it flicker or does it happen in a pattern like the ballast / power pack is warming up then firing then shuts down
i would start with the power pack
unplug it and open it up wiggle the connections could possibly be a bad soldier connect or connector if it is shock sensitive and comes on when you bump the unit when its plugged in

@ tekdc, i bumped gently and got nothing out of them. The two leds flicker very very dim in like .25 second intervals. i will open later and wiggle them cables. Good point.

Well it looks like you have sections in that panel divided equally. So my guess is you have 4 drivers also.

Either the driver is bad or the LED's in that series have gone kaput for one reason or another.Or loose wire connection.

Only way to find out is to open it up (disconnect power first ) and test each LED with some AA batteries to find out if it's the LED's .

This is what I used to test my LED's ( Rapid sent it with my order for free ) . Just touch the + and - leads to the + and - on LED. Or build your own tester.
http://www.rapidled.com/led-testers/

PS: Seems these type of threads of chinese lights failing are becoming common. They use the cheapest parts so don't expect them to last long. When
I was emailing chinese LED companies and asking about what type of Drivers..heatsink specs and wire gauge etc I never did get an answer.

@ Rainerocks, great advice on testing individual leds. will open it up and check for loose connections, if i dont find anything i will test leds with your battery method. Lets say the connections are good and the leds do turn on with the battery test, would the next step be to change the driver? thanks a bunch

Have you opened it up yet? That's going to help everyone tell what's going on. Plus you can swap drivers to see if it's a bad driver or not. I hope it's not a Blackstar type of panel with bad diodes. You gotta have patience to fix those.

@franjan, havent opened it up yet, will run some tests first than if all else fails, i will purchase a driver from somewhere. Let me know a good spot to buy these components. not blackstar, these things are spectra by mike; back when he was honest and tried a little harder.

Thanks you guys. I will update in the next couple of days.

 

[FranJan]

Mehrific you may want to use a multimeter to test the LED connections. The battery test doesn't work too well on some blues and FRs from what I've seen. Do you know the voltages of the diodes? If you don't have some resistors you could fuck up the diodes testing them with batteries. Especially since it's an older panel. Maybe it's a grounding wire or something is shorted. I've seen the flickering behavior in a shorted panel, and sparks too . And when I see that foil it usually means it's that PCB with holes technique they use to mount the diodes on the heatsink. A design that is very susceptible to shorting I might add. Get your screwdriver out Meh, the game is afoot and it's going on inside your panel . It's the only way to test the drivers, though I wouldn't plug a good driver into that section till you know it's not a short. And again a multimeter will make testing the driver safer. Good Luck!

 

[mehrific]

thanks franjan for the heads up, they are 3 watt leds. Ill let you know what i find. Im sure i will have more questions when i begin the operation.

 

[tekdc911]

he makes a good point your series probably starts with the 2 that are trying to fire then shorts out behind them but could be a weak driver but you'd figure more then 2 would be atleast dimly lit i think he hit the nail on the head with the short against the heatsink

if you were to put your meter on ohms and test from the start of the series to your heatsink it would give you a idea if its shorting
if it shows continuity then you have a short

 

[tekdc911]

he makes a good point your series probably starts with the 2 that are trying to fire then shorts out behind them but could be a weak driver but you'd figure more then 2 would be atleast dimly lit i think he hit the nail on the head with the short against the heatsink

if you were to put your meter on ohms and test from the start of the series to your heatsink it would give you a idea if its shorting
if it shows continuity then you have a short

lol you can tell when im smoking Amnesia i talk in circles lol

 

[mehrific]

I have narrowed down the problem to what i believe is a 500mA driver. Reason i know this "driver" is bad is because i switched connections and whatever connection this driver is plugged in to corresponding led strip will not function.

This is the panel: (below)
Might be hard to see but the highlighted corners is where leds do not function. I checked for shorts on all led connections and the board. Nothing fishy here.


LED panel guts:
As you can see it is all nicely snug.


Culprit Mugshot:


Question is................. where can i find this part. Can i use any 500mA driver off of ledsupply.com. Can i fix this one. Any ideas are welcome. Thank you.

And another quick question.

The current heatsink looks like a cheap flat 5mm thick aluminum layer attached to the board. Can i add a heatsink by simply using some thermal adhesive and gluing it on top of the existing heatsink? Will I notice a significant increase in lighting?Or should i not bother?

 

[Mechmike]

Hi I've just been reading your thread. You can use a constant current driver up to 700ma. Most manufacturers opt for somewhere in the neighborhood of 550-650ma for the Chinese 3 watt diodes. It's important to size your driver right by the potential voltage it produces. A good rule of thumb is that the dioodes will use an average of 3.3v each. So, if you have a string of 10 diodes you will need at least 33v. Constant current drivers typically have a wide range of voltage at the regulated amperage so a driver that that is 24-42v @600ma will power 10 leds nicely.

I've considered doing the same thing to a few of the so-called flat heat sinks I have encountered as well but decided against it. I just tell everyone to make sure to look inside the light before you buy it to make sure the folks that built it used a real heat sink.

 

[mehrific]

Thank you mechmike,
This one driver powers 24 leds out of 144. Im sure these diodes work below the average voltage since 24 x 3.3v is close to 80v. Most drivers i have found go up to 42v like you mentioned above. Is there any way i can check the voltage from a single diode? Another question....can i disconnect the malfunctioning driver and run the remaining lit leds without burning something out?

 

[FranJan]

^^^You can run them with little worry like that. If anything your cooling will be better . I've had drivers go out and the only problem with running them this way was the was the panel was even shittier than before . If you have a multimeter you can just get a reading from a working driver/series then just contact a few Ebay vendors and ask if they have a driver that will work in your setup. And to be on the safe side I think you should take the average voltage of each color in the series and add those together if you go the guesstimate route.

 

[lax123]

those Drivers look not very trustworthy, better get some ip68 stuff.
forwardvoltage decreases while those leds r heating up.

get a multimeter. with it u can check forwardvoltages, mA, see if diodes r working, and also what that faulty Driver is doing or not doing (reading its voltage and power Output)

typical red Vf is like 2,4V @ 700mA, @ 600 or 500mA iits even less...

 

[Mechmike]

Thank you mechmike,
This one driver powers 24 leds out of 144. Im sure these diodes work below the average voltage since 24 x 3.3v is close to 80v. Most drivers i have found go up to 42v like you mentioned above. Is there any way i can check the voltage from a single diode? Another question....can i disconnect the malfunctioning driver and run the remaining lit leds without burning something out?

You're welcome!
If your led string is 24 you will not likely find a single 500-700ma driver on ebay to replace it with. You probably have 1 diode out. If you want to save money you can bypass (wire around) the open led. You will still have 1 led out but it should not affect the 23 remaining on the string. If you use a multimeter you can test the diodes individually to determine which one is out. Alternatively, you could carefully jumper around each led on that string while energized to determine which one is open. Just don't use a bare wire...

 

[mehrific]

Thanks fellas! Good info from all of you.