Aqua Knight LED chip replacement.

[oreo54]

Are you measuring the square?

 

[SashimiTurtle]

Are you measuring the square?

Yes... no solder inside the caliper.

 

[oreo54]

Fuzzy caliper pic looks more like you are measuring the dome. My mistake.
Package is measured so I assume yours is square.

 

[SashimiTurtle]

Fuzzy caliper pic looks OK more like you are measuring the dome. My mistake.
Package is measured so I assume yours is square.

Yes I checked both ways. 3.3mm square. They are cheap calipers so I wasnt expecting them to be super pinpoint accurate.

 

[BrandonS]

Correct me if I am wrong but the drivers are also important. A blue LED runs at a higher voltage than a white or red LED typically right? so 4.2 vdc for blue and UV and white,red would be something like 3.5 vdc.

 

[SashimiTurtle]

Correct me if I am wrong but the drivers are also important. A blue LED runs at a higher voltage than a white or red LED typically right? so 4.2 vdc for blue and UV and white,red would be something like 3.5 vdc.

I'll check with my volt meter after dinner

 

[SashimiTurtle]

I cant see anything but blue dots right now, but they are all running about 3V. The blue channel is at 2.9V and the white is 3.0V.

 

[oreo54]

Correct me if I am wrong but the drivers are also important. A blue LED runs at a higher voltage than a white or red LED typically right? so 4.2 vdc for blue and UV and white,red would be something like 3.5 vdc.

Red diode V(f) is usually <3V,
drivers matter but not exactly the way you think.
At constant current (which looks like these drivers are designed for) it regulates the current by raising or lowering the voltage to the diode so..voltage needs of the chip aren't an issue.
Blues/whites (reallly blue plus phosphor) are generally 2.8-3.7V
violets higher.. around 3.6-4.2
All depends on drive current of course..
not to mention different "bins" of the same chip can be different..

A note though different "classes" of diodes i.e 1/2W. 1W 3W can all have the same voltage..
Actually the more important thing to know would be the driver current output at 100%..
That and the voltage will determine the "diode class"... i.e 3V @ 700mA = 2.1W i.e "3W class"
high end is the only important thing though..a 3W class may run fine at 1 or less watts.. w/ obviously decreased output..
1W "class" diodes will prob live a short life at 2.7W output.

Some drivers have a minimum voltage so like a single red diode may not allow it to function.
Also most have a top end sooo too many diodes in series, same thing.

It's kind of "messy"..but relatively simple.

 

[SashimiTurtle]

Tried before work to remove a chip with a butane torch I picked up. Heated the board from underneath and never could get the chip to budge. The whole board was hot enough I could not touch it. I believe this may prove difficult to do. The size of this board is acting like a heat sink.

 

[oreo54]

Got an electric frypan?

Reflow Skillet - SparkFun Electronics

www.sparkfun.com

some have used cast iron on a stove..

 

[SashimiTurtle]

Got an electric frypan?

Reflow Skillet - SparkFun Electronics

www.sparkfun.com

some have used cast iron on a stove..

I have a large flat griddle, and a gas stove that would heat that board right up... but there are resistors and I believe controllers on the board as well. I'm not sure how well they would hold up to 900 + degrees.

I have a few more night shifts to go, after that I'll really sit down and try to heat under one of the diodes and see if I can get it to come lose. I also just got my solder paste in the mail today before work, so maybe if I can put a dab of fresh solder next to one of the chips, it'll help to get the rest to melt.

I haven't ordered any chips. I'm still deciding on what colors and really want to get one of them lose to be sure what type it is. I'm really leaning Cree XP-E2 after measuring them, but they may still be XBD as that is what is advertised.

 

[oreo54]

Heat needs to top at about 410F..of course the orig solder determines actual temp.
Reading some of th comments .. a thin layer of sand will help distribute the heat more evenly..

 

[SashimiTurtle]

Heat needs to top at about 410F..of course the orig solder determines actual temp.
Reading some of th comments .. a thin layer of sand will help distribute the heat more evenly..

I'll let you know how it goes when I get a few days off. Thursday may be busy but nothing to do Friday. I'll try and tear it apart for sure then, if not before.

 

[oreo54]

Just be careful since when your diodes you want to remove are ready.. so will many of the others..

 

[SashimiTurtle]

Just be careful since when your diodes you want to remove are ready.. so will many of the others..

I was thinking about that. If I can remove the resistors and other circuitry from the PCB, then I can heat the entire board up on the griddle and change all the LEDs at once... maybe...

 

[oreo54]

Well heat it twice. Prob no way to remove then place diodes..without burning up the boards..

 

[SashimiTurtle]

It's done. Well one is. Ordered LEDs from Digikey. They are Cree XP-E2 chips. I used a grittle that I used to use to cook breakfast on, on top of my gas stove. Placed the PCB board down and started heating. Chip colors are as follows.

Channel 1
2 3000K warm white
2 5700K neutral white
1 6500K cool white
1 530nm green

Channel 2
2 660 red
1 475 blue

 

[BurgerFish]

So, the default diodes are Cree XP-E2?

 

[SashimiTurtle]

So, the default diodes are Cree XP-E2?

Man this feels like it was forever ago... 2020, **** yes that was forever ago. According to my last post on here that was the chip i used. That light is still being used over a IM 20g drop off with anubias, bacopa and Amazon swords. All growing like crazy. One of the anubias is trying to grow out the tank and I need to thin out the swords. I also lost my panda garra in there so I have a little algae starting to grow.

 

[BurgerFish]

@SashimiTurtle

Do you have any idea about diode voltage? 3.1, 2.94 or 2.85?