4x2.5 cab outfitted with a diy cxa3070 build

Mechmike

Mechmike

Well-Known Member
Al Yamoni said:
So I tested the board and found 4 dead leds out of a total of 168.
View attachment 3288562
#'s
39
104
110
136
Looking at the pic, what is my best course of action at this point? I'm reading that I can solder a wire bridging the anode and cathode, but is this my only option? My soldering skills aren't the best just yet even though I've been practicing..
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That type of board is pretty easy to repair. To de-solder an led, just apply a small amount of pressure to the top side (lens) of the diode while melting the solder on each lead. The leads on your new diodes will have to be flattened so they will rest evenly on the board. I usually trim the diode leads a bit so they fit perfectly. Once you have the diode on place just touch the leads with a hot iron and a touch of solder. That's all there is to it.
If you want to run softer you can use one like this http://www.ebay.com/itm/LED-Driver-Power-Supply-for-36pcs-1W-High-Power-LED-18w-36w-18-36-x1W-LED-/221255343940?pt=LH_DefaultDomain_0&hash=item3383d89f44. I have done the same with Chinese 3w lights. It does reduce the amount of light but not by 50%. It's more like a 30% reduction. You are right about the reliability. They don't seem to fail when driven soft.
 
SupraSPL

SupraSPL

Well-Known Member
Al Yamoni said:
So I have a 200mm 3 speed pc fan and a few acdc adapters. The first one I hooked up wouldn't power the fan. Its output is 12vdc @1.2A which I thought would be more than enough.

The one that ended up working was rated at 110-240v @1A output. Why did this one work and not the other?
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Just to be thorough, did you try swapping the positive and neg? Sometimes manufacturers code the wires backward from the others. It is also possible that you came across a dud.
 
Al Yamoni

Al Yamoni

Well-Known Member
Mechmike said:
That type of board is pretty easy to repair. To de-solder an led, just apply a small amount of pressure to the top side (lens) of the diode while melting the solder on each lead. The leads on your new diodes will have to be flattened so they will rest evenly on the board. I usually trim the diode leads a bit so they fit perfectly. Once you have the diode on place just touch the leads with a hot iron and a touch of solder. That's all there is to it.
If you want to run softer you can use one like this http://www.ebay.com/itm/LED-Driver-Power-Supply-for-36pcs-1W-High-Power-LED-18w-36w-18-36-x1W-LED-/221255343940?pt=LH_DefaultDomain_0&hash=item3383d89f44. I have done the same with Chinese 3w lights. It does reduce the amount of light but not by 50%. It's more like a 30% reduction. You are right about the reliability. They don't seem to fail when driven soft.
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I'm looking at this driver simply trying to wrap my head around matching the right drivers for this build so I don't have to rely on others input for future builds.

Anyways, will the driver linked work for one of my strings of 42 3w leds? Keeping in mind that I want to run them softly..

(I've read the diyleds and how to power them thread. I'm just really "simple" I guess...)

So I add up the vF of each led on the string and make sure the driver outputs that many volts? What about the mA? How do I factor that into the output of the led or the led string?
 
FranJan

FranJan

Well-Known Member
You know Al, Mike is right about it being an easy fix, he just left out that it's an annoying fix :sad:. Those effin screws really make it a pain in the butt :-x and as a person that's fixed his own BS240s on many occasions I can confidently say that when diodes start blowing it's usually a sign that more are to follow. Basically if you do manage to jump or replace those diodes, re-apply thermal grease to each diode and manage to screw it all back together without shorting the LEDs to the "heatsink", within the month another diode will probably go and you'll be back to screw hell :wall:.

First gen Blackstar's drivers run at something like 580mA, maybe 630mA, so running them at 350mA would be running them softer but that kinda takes away from what makes BS works and it's intensity, not efficiency that is the backbone of budget panels, (and don't even talk about proper spectrum with that cooling system of theirs :)). I think you'd be better off just chucking the BS diodes and buy some smaller COBs that would fit that heatsink and make a panel from that. I took my BS 240s and turned them into overdriven Illumitex panels. I was going to replace the BS LEDs with Avago LEDs which are similar in design to the Chinese gull wing used by BS but it would have involved lots of modding so I said fuckit.

So all I can say is you may want to think twice about repairing the panel and just scavenge the sucker for parts.
 
Al Yamoni

Al Yamoni

Well-Known Member
I appreciate the input Fran! I'll most likely be moving forward but if it goes to crap then I won't take it too hard based on your suggestions.

I want to run this particular light in my 2x2, and at full power and full exhaust speed I can't get it under 87F in there.

I think that toning down the amperage to 350mA and executing a better cooling design will allow it to last much longer. At least enough time to satisfy my usage of this light weighed against what I paid for it. Also it will be caseless for simplicity and to help with cooling.
 
Al Yamoni

Al Yamoni

Well-Known Member
So my 3w diodes have a vF of 2.8 max and run at 700mA. If I want to run 42 in a string softly at 350mA I would calculate:

2.8*42=117.6V

So then I would need a driver with an output of up to 120V @350mA?

Is there more to this that I am overlooking?
 
FranJan

FranJan

Well-Known Member
If you know the Vf max of the LEDs then as long as your driver provides AT LEAST that then you're golden. So in your case any driver that does at least 118+ volts at 350mA it will work. Try to get something bigger than 125 volts just so you're not running the driver at it's limits and producing more heat than you want it to. Higher efficiency drivers will also generate a little less heat.

700mA huh? I'm surprised BS panels run at 700. Where did you find out that they run at 700mA btw?
 
Al Yamoni

Al Yamoni

Well-Known Member
That's just the max that the diodes can handle(what I read). The drivers in my 500w veg model state that the output is @650mA
 
Mechmike

Mechmike

Well-Known Member
Al Yamoni said:
So my 3w diodes have a vF of 2.8 max and run at 700mA. If I want to run 42 in a string softly at 350mA I would calculate:

2.8*42=117.6V

So then I would need a driver with an output of up to 120V @350mA?

Is there more to this that I am overlooking?
Click to expand...
Your math is good. The driver you linked to has a bit different specs than the one I linked. The input is 175-245vac and the output current is 300ma on the one you suggested.

On a constant current driver the current stays constant as in 350ma. So, look for a driver that has the correct input voltage for your country, the current you want to drive at and enough forward voltage to power the VF of the entire string. For your strings of 42, 120v output should be a minimum.

The 2.8v figure is a rough average of the VF used by the typical mix of mostly reds and blues. The reds typically use ~2.5v. The blues and whites typically use ~3.5v. There are usually about 4:1 reds/other colors.
 
Al Yamoni

Al Yamoni

Well-Known Member
Thanks again! I really appreciate you taking the time to word it in a way that I can understand! I think that I got it now!

The one that you linked is obviously a better choice, I was just showing that model to wrap my head around the specs and how they factor in.

Time for more reading.
 
Al Yamoni

Al Yamoni

Well-Known Member
Mechmike said:
That type of board is pretty easy to repair. To de-solder an led, just apply a small amount of pressure to the top side (lens) of the diode while melting the solder on each lead. The leads on your new diodes will have to be flattened so they will rest evenly on the board. I usually trim the diode leads a bit so they fit perfectly. Once you have the diode on place just touch the leads with a hot iron and a touch of solder. That's all there is to it.
If you want to run softer you can use one like this http://www.ebay.com/itm/LED-Driver-Power-Supply-for-36pcs-1W-High-Power-LED-18w-36w-18-36-x1W-LED-/221255343940?pt=LH_DefaultDomain_0&hash=item3383d89f44. I have done the same with Chinese 3w lights. It does reduce the amount of light but not by 50%. It's more like a 30% reduction. You are right about the reliability. They don't seem to fail when driven soft.
Click to expand...
This is the best driver for my situation that I can find after plenty of searching. Thanks again brotha.:bigjoint:
 
Al Yamoni

Al Yamoni

Well-Known Member
Mechmike said:
Those would work but it would be sort of defeating the purpose of keeping the repair within the value of the light.
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Exactly. Just making sure that I can correctly pair a driver for a given situation. Now to get some moolah for those sweet $9 Chinese models...
 
Al Yamoni

Al Yamoni

Well-Known Member
I think that I am going to try and calculate the vF of each type of led on the string to make sure that I'm cutting it close enough and not jumping overboard.
 
Mechmike

Mechmike

Well-Known Member
Al Yamoni said:
I think that I am going to try and calculate the vF of each type of led on the string to make sure that I'm cutting it close enough and not jumping overboard.
Click to expand...
I can give you a first hand confirmation that those drivers will work. I retrofitted a Chinese 3w light made by a different manufacturer last year that has strings of 42 diodes running off those very same drivers with roughly the same mix of colors. The light hasn't failed since.
 
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