Radion Lights Board Level Repair

[_AV]

I enjoy an occasional board level repair. It gives me a new angle to this hobby, which is often very heavy on DIY. In this thread I'm going to post some of my more interesting and challenging repairs, picture heavy, including high magnification microscope imagery.

Recently, I got ahold of a used Radion XR15 Pro Gen3 which doesn't work. It powers up and starts blinking the LEDs but never gets them to a solid ON state. So it's time to take it apart and look inside! XR15 contains only one LED puck, it's attached to the aluminum body of the light with a fan at the top. Positioning the fan at the top, while all of the electronic components are underneath resulted in some design challenges that eventually contributed to this failure. So Let's take a close look!

The main board appears to be functioning just fine at all test points. No shorts and all voltages seem to check out. So why would all the lights blink constantly? Well, it turns out not all of them actually blink. The four LEDs at the perimeter closest to the edge are always off. This is odd... Looking closer at those LEDs revealed the first clue: corrosion. Time to desolder the LED in question:

What you see above is the LED completely removed. The liquid in place is just some soldering flux used. And through this flux you can see that the entire LED pad is covered with a thick layer of corrosion.

But where did the corrosion come from?

Ecotech has to power the fan somehow. To do so, in XR15, they decided to add the fan power connector to the LED puck. The fan wiring needs to go through the aluminum body to connect to the puck. There is a fairly large hole in the aluminum body to run the wiring (which is likely due to the size of the male connector) and a corresponding hole in the puck itself. You can see that the hole was partially covered with a small piece of capton tape. When the fan spins, it constantly pumps air through this small hole, the tape eventually gets unglued and the air rich with salt crystals makes it's way onto the LED puck. The corroded LED is right at the edge of the pole in question.

Now that we know the problem, it's time to fix it!

The corrosion didn't just disconnect the LED from the board, it was bad enough to partially destroy the copper pad as can be seen here after most of the corrosion was removed:

An additional challenge was that the positive lead is completely disconnected from the pad on the PCB.

The LED itself was not in much better shape. The bottom pads were also partially corroded. It's not worth saving the LED itself.

The pads have been cleaned up and tinned with nice clean new solder and ready to accept a new LED. However, the positive lead is still damaged preventing any voltage getting to the new LED. Luckily, we can run a jumper wire right to the LED:

And with that, the XR15 is happy again!

The wiring hole will be properly sealed to prevent future salt creep making it's way to that side of the board.

 

[stefanm]

Good work, just fill the hole with silicone where I live we get these 20ml tubes of rtv silicone that are dirt cheap.

 

[_AV]

Yes, RTV is a great option as it's rated to 400F. However, we need to make sure the fan is still serviceable. So instead I use small heat resistant silicone plugs cut half way, snapped around the wire and pushed into the hole.

 

[_AV]

While assembling the light, I've noticed that a pin is missing from the puck connector to the main board. what the heck? It looks like this light has prior repair damage! The missing pin provides power to the fan. Not good.
Also, the pad on the board got ripped away with the pin.

Normally, in this case I'd just replace the entire connector. But this time I didn't have any on hand, so need to improvise.
a similar pin from another type of connector was cut to size and inserted into the plastic housing.

Since the original pad is gone, I cut the connector extra long so as to avoid using a jumper wire to connect it to the trace.

This way I have a nice, simple and strong solder bridge. Final assembly and testing for continuity. Everything checks out.

This poor light has been through a lot. But now not only does it have a fully working LED puck but also a functioning fan.

 

[theatrus]

Very good repair article!

From repairing some salt water damaged equipment before, I'd like to leave one personal cautionary tale:

When dealing with fiberglass boards (most electronic control boards, not LED power boards), salt will soak into the FR4 very slowly. If you're dumb like me and say "I'll give this a quick wash in the ultrasonic", without doing a lot of rinsing and removal of salt on the surface, expect that large areas of the FR4 will actually become fairly conductive. Enough to burn holes along tracks as it heats up.

So, either only clean the very surface, or if you want to do a major cleanout, so a _lot_ of wash steps to remove _all_ the salt and then put it into a drying oven for a long time. And maybe do it all again.

I tossed the board I destroyed that way, but it was entertaining finding the issues by trying to jam 10-20A through the board to burn out the near-shorts (10s of ohms) all over the place :-D

Also, if you're building boards, please conformal coat them. I'm looking at nearly every manufacturer out there who doesn't do this (EcoTech, Neptune, etc included). In fact the only conformally coated boards in the aquarium industry I found were from Kessil (potted with silicone). Salt gets in everywhere.

 

[_AV]

Thanks, @theatrus! Very timely advice. I have just that type of board for my next repair project
Did one round of ultrasonic cleaner already. More to come soon.
What "detergent" did you use for your ultrasonic bath?

 

[theatrus]

Thanks, @theatrus! Very timely advice. I have just that type of board for my next repair project
Did one round of ultrasonic cleaner already. More to come soon.
What "detergent" did you use for your ultrasonic bath?

My go to is Branson EC, though usually thats for cleaning up super messy flux rework. It also will etch aluminum so not suggested for metal boards.

For salt, I'd probably just go with a round of DI water first, dump it, and then use a solution.

 

[_AV]

Sounds like you are into this as well. I use Branson EC also, it does a very good job in a decent cleaner, but still requires some additional manual brushing for heavily damaged boards. I also use an alcohol bath to displace any water left from Branson and DI cycles.

 

[stefanm]

Very good repair article!

From repairing some salt water damaged equipment before, I'd like to leave one personal cautionary tale:

When dealing with fiberglass boards (most electronic control boards, not LED power boards), salt will soak into the FR4 very slowly. If you're dumb like me and say "I'll give this a quick wash in the ultrasonic", without doing a lot of rinsing and removal of salt on the surface, expect that large areas of the FR4 will actually become fairly conductive. Enough to burn holes along tracks as it heats up.

So, either only clean the very surface, or if you want to do a major cleanout, so a _lot_ of wash steps to remove _all_ the salt and then put it into a drying oven for a long time. And maybe do it all again.

I tossed the board I destroyed that way, but it was entertaining finding the issues by trying to jam 10-20A through the board to burn out the near-shorts (10s of ohms) all over the place :-D

Also, if you're building boards, please conformal coat them. I'm looking at nearly every manufacturer out there who doesn't do this (EcoTech, Neptune, etc included). In fact the only conformally coated boards in the aquarium industry I found were from Kessil (potted with silicone). Salt gets in everywhere.

Can the conformal coating be sprayed on finished boards? In the past few months we had 15ft of rain instead of the average 8-10ft (June to October) humidity at saturation point, first an Arduino popped controlling my lights, took out 5 mean well ldd's with it and a PCA 9685 module! Managed to hook it up to my reef-pi, replacement drivers took around a month to receive ( a friend had surplus and kept forgetting to send, then his neighbourhood was completely locked down) after that was sorted my mean well lrs smps went out with a very loud bang, I send it to their local office and they refused warranty, I had ordered a replacement PSU which took 20 days to arrive, in total I had close to 6 weeks without lights, lost quite a few corals.

Oh yeah, mean well or as I say well mean, said the lrs needs to be in an enclosure! And it had been "brutally used"

So can the coating be sprayed on the components also?

 

[_AV]

Yes, there are sprays that you can buy to do this. Acrylic, silicone and urethane sprays come to mind. Need to be mindful of where you apply it though.

 

[theatrus]

Yup, most components can be coated. Many acrylic coatings can be "burned through" with a soldering iron which still lets you rework the boards without a lot of pain. The challenge is of course connectors - you either need to solder them after coating (with a coating you can burn through) or mask them off well when coating.

I'd start with a simple spray on or brush on acrylic, which is pretty cheap in small quantities. Most dry really fast (minutes) and are pretty thin so easy to spread.

 

[lumbeejerk]

Could you check one out for me if I ship it to u

 

[_AV]

Could you check one out for me if I ship it to u

I sure can. Replied to your PM.

 

[_AV]

I get radion lights with this specific problem periodically. Finally got around to record a repair video on this specific problem:



Interestingly, in both repairs the RF module was incorrectly plugged in. Likely an artifact of a previous repair attempt.

 

[User03938301]

From where did you get the proper value for the measurments, when testing with the measuring points?

 

[_AV]

From where did you get the proper value for the measurments, when testing with the measuring points?

Usually, from known good lights. Also sometimes from datasheets.

 

[User03938301]

Usually, from known good lights. Also sometimes from datasheets.

Are there datasheets for this led? I am asking, because my own led has the same fault(flashimg red) .

 

[_AV]

Are there datasheets for this led? I am asking, because my own led has the same fault(flashimg red) .

Not publicly available, not for the light. But there are public datasheets for individual components.

 

[User03938301]

Could you send them to us?
ot publicly available, not for the light. But there are public datasheets for individual components.se

 

[_AV]

Could you send them to us?
ot publicly available, not for the light. But there are public datasheets for individual components.se

No, I can't do that unfortunately.