For thr one boaard where nothing lit, are you sure you had the polarity correct?? A minor error like that could confuse things.

Yes sir, I can understand that, but sure that I checked correctly.

 

Not having any luck with in-line searching for anything remotely similar. But…this Chauvet company does have a newer, similar light bar. Looks like it could be using individual panels like mine, but they only have 35 LEDs. Pretty cheap—somewhere around 65 dollars and up would get replacements. (If they could be modified to handle the higher voltage meant for the 45 lamps?)
And since each of them are clear lamps, they must actually be color LEDs, since they emit the same color regardless of which channel they are connected to?

 

Ordered one of these newer light panels. Should be here Wednesday or Thursday. We shall see.

 

I will be interesting to see how close it is to the older ones. Have you given up attempting to fix the older ones??

 

Ordered one of these newer light panels. Should be here Wednesday or Thursday. We shall see.

Make a video, Please!

 

I will be interesting to see how close it is to the older ones. Have you given up attempting to fix the older ones??

No I haven’t given up…yet. Seems so simple, but yet I’m just not clued in enough. First, it blows my mind that somehow (it appears) that all 45 LEDs are bad. As you said, simply applying a little power to them should show good or bad, and that appears to be total failure. I found another LED in my parts junk and it powers up fine with the little 5v supply…Let me ask this, just in case…when I tested each LED while still on the board, I touched each leg with the appropriate power leads. With them still being all tied together on the board, does this affect the outcome of bad or not?
I need to study the whole unit again—I believe this particular LED board have the lamps being a color. (When I switch boards around, the color stays the same) so I know that affects total supply voltage to a degree)
When this new unit arrives, it’ll have 35 LEDs instead of 45, so if I could use it, I’m thinking I’d have to either add something to lower total incoming voltage, or add 10 more LEDs?…

oh, and time hasn’t been good to me lately—trees down from storms I’ve been cleaning up, tractor broke down and had to go arrange new one, other fixes…LOL kinda interrupted my lighting problem

 

With them still being all tied together on the board, does this affect the outcome of bad or not?

No. Not unless there's a complete circuit. But with 45 LED's even a complete circuit would have very little effect on the one under test.

When this new unit arrives, it’ll have 35 LEDs instead of 45, so if I could use it, I’m thinking I’d have to either add something to lower total incoming voltage, or add 10 more LEDs?…

LED's are controlled by current, not voltage. Yes, you will have to reduce the "Current". That might be achieved by lowering the voltage or it might be achieved by - if a constant current source is used - change that current source; OR by adding appropriate resistance. HOWEVER, adding resistance means increased heat. AND the appropriate size (in wattage) is necessary too.

trees down from storms, I’ve been cleaning up, tractor broke down and had to go arrange new one

That stinks. Just goes to prove that when it rains it pours.

 

There is a possible chance that the LEDs may actually need a higher voltage, although that is just a guess. You could try oneor two with the five volts direct, very briefly, and see what happens.

Certainly you will need to know the specifications for the new LED panels, because there may be a difference, as you have commented.

 

It came today! Anxious to tear into it and see what we have. Pics and info coming shortly.
(also see another new post I just added—another failure! My ultrasonic cleaner quit! And I need a carburetor cleaned! )

 

It came today! Anxious to tear into it and see what we have. Pics and info coming shortly.
(also see another new post I just added—another failure! My ultrasonic cleaner quit! And I need a carburetor cleaned! )

Imagine doing that every workday for 30+ years.

 

Hmmmm…the new DJ Bank light bar was physically smaller—about 2” or more on each end, compared to the older Stage Bank piece. And we knew the new one has 35 LEDs compared to the 45 in the old one. I believe the new panel runs at 94v, printed on the panel, and inside the case on circuit board. Both have all clear LEDs but each section/panel have either red, green, blue, or amber LEDs. They appear to be the same size physically. The new one isn’t separate panels, but all in one pane. You can see on the new panel at the bottom the letters for the colors below each group. (R G B A)
I took my little power supply and once again tried each individual LED in the old panel, and all were dark. I did the same on the new panel, and each LED did light.
So…after all that and the mess I’ve led you through I believe I’m better off just ordering at least 45-50 yellow LEDs and put them on the old board. Remember, in the old light, I swapped the good panels around and all worked fine, and on the same power lead where the bad panel came from….
I’ve spent several hours searching foreign sellers to try and find replacement panels but no luck. Some similar, but not close enough. I’m thinking there has to be more out there, but finding them
(Some years back I was repairing an old radio broadcast console—6 of 12 channels weren’t working—somehow I traced it down to a single chip. None existed in the USA, except one fella in FL had one, and he wanted 30 bucks for it! Somehow I found a China company that had them. I ordered them, at a whopping 2 dollars apiece. Added 20 bucks for faster shipping and had them in 4 days. Worked great and still have that console today!)

 

Here are some pics:

 

And more:

 

I believe the new panel runs at 94v, printed on the panel

94V is an odd voltage. Not that it's impossible, but be certain before you power it. To my experiences with PCB's 94V 0 typically was the fire rating of the board and not reflective of the voltage it operates at. So be careful you don't blow the new boards out.

 

94/35 = 2.6V (new board)
94/45 = 2.1V (old board)

The second is about the right voltage for amber LEDs of that type. 2.6V might be right for higher power amber LEDs.

It is a bit of a puzzle that all 45 LEDs would blow at the same time without obvious physical damage.

I presume you checked the LEDs with both polarities, right?

 

The odds that all of the LEDs are bad is almost astronomical.

Perhaps a patina on the solder joints...I don't know, just shooting in the dark.

 

I presume you checked the LEDs with both polarities, right?

Wondered the same thing. THAT inspired me to imagine a 24VAC source with a 1K5 resistor. 16mA shouldn't hurt an LED. The reverse voltage shouldn't cause any problems either. And regardless of the polarity the LED will still light.

Going to test this in minutes.

 

OK, using a 24VAC Wall Wart, a 2KΩ resistor (1/4 watt) and a Super Bright LED, White with a forward voltage of 2.97V, the LED lights up with either polarity. It works! Current should be 10.5mA and 252mW. A quarter watt resistor is fine for the brief test. It's not going to overheat unless you leave it running the LED for longer than just verifying it is good. The great thing about testing in this manor is you don't need to worry about polarity.

 

CAUTION!!!! The reverse voltage limits for many LEDs are lower than for normal diodes!!
So, which I should have suggested with my testing post, would be to measure the led VOLTAGE ON ONE OF THE WORKING PANELS. THAT would be the simple way to have an understanding of what voltage to apply. The early RED LEDs could not withstand a reverse voltage of ten volts. So if you try it on a good LED you may get a flash. Or maybe not even that.

 

The early RED LEDs could not withstand a reverse voltage of ten volts.

Stage Lighting? Certainly not going to be old style LED's. The super bright LED I just tested had no problems with 24V reverse volts.

I agree with your caution, especially with old red LED's. But we're not dealing with old red LED's.

I'm still trying to find a reference that would give an idea of what LED reverse current breakdown voltages are. But since the resistor is dropping so much voltage the reverse shouldn't be anywhere near breakdown.