PopBloom Shannon s50 light issues

[bishoptf]

@Sral @oreo54 and anyone else I am looking for some circuit insight as to how I can figure out what is fried in a lighting circuit. I have several of these Popbloom Shannon S50 led lights. They are pretty basic lights but I have couple of shallow tanks and they do good enough. They have a circuit where they have 4 channels and a sunrise sunset timer function. I have a bunch of pictures but one of the issues with the LED layout is that one end is not as bright as the other and I had 2 of them end to end and I needed to swap around the unit but they have the plug coming out the end of the one I wanted to have butted up against the other. I have a spare unit so I thought I would just feed the 24v from the one end to the other, see pictures. Pretty easy I thought. I had things wired up but when I plugged in the power supply nothing happend, no led's came on. So I started poking around and it appears that when they decided to wire the 24v plug up Red was negative and Black was positive, sigh. I know I should have checked it but really why would they reverse the colors. Is Red not universally positive etc? I corrected that but now when I plug it in the led's light briefly and then go out, and when I mean briefly its very short blip. My question is what could I have fired by feeding it reverse polarity 24v. I have a bunch of pictures that are attached and I see where 24v comes across the board I'm just not sure how to attack this and figure out what needs to be replaced, which if I can figure that out I can correct it.

Any help or suggestions welcome!

 

[Sral]

Nice catch … at the end ^^

First thing is probably any polar component, so any electrolytic capacitor (which you don’t appear to have) or semiconductor component. The latter includes diodes, transistors and chips (regulators probably classify as chips as well).

Chips have input „protection“ sometimes, e.g. diodes that keep the lines where they should. Those would probably burn if used incorrectly, likely becoming permanently conductive or unconductive consistently.

I’d try measuring the diodes with a multimeter first and then see if the regulators still put out what they should when you connect voltage. That’s a risky business though, since even correct voltage might now burn other components through the damaged ones (maybe I’m paranoid on that).

So maybe start with low voltages if possible and see if the regulators keep their target after input passes it.

 

[bishoptf]

Nice catch … at the end ^^

First thing is probably any polar component, so any electrolytic capacitor (which you don’t appear to have) or semiconductor component. The latter includes diodes, transistors and chips (regulators probably classify as chips as well).

Chips have input „protection“ sometimes, e.g. diodes that keep the lines where they should. Those would probably burn if used incorrectly, likely becoming permanently conductive or unconductive consistently.

I’d try measuring the diodes with a multimeter first and then see if the regulators still put out what they should when you connect voltage. That’s a risky business though, since even correct voltage might now burn other components through the damaged ones (maybe I’m paranoid on that).

So maybe start with low voltages if possible and see if the regulators keep their target after input passes it.

Oops I had no idea that made it in the posting, and I can't go back and edit...to funny (5lb bass I caught last wednesday). I think I may have figured it out. 24v comes in at the other end and travels all the way across the board and positive comes in to that adapter board where I have highlighted orange box. I originally thought it was a resistor and got some alcohol and tried to clean it up and thought it looked like a tiny fuse. I have +24v coming in and and get almost nothing on the other side and its odd like it starts at .5v and goes almost to zero. Could this be a schottky diode or something like that and when I reverse polarity it fried it? Just for grins I plugged it in and took my alligator clips to jumper the connection and all the leds lit up...so I think I have found the culprit but not sure I know what it is that I need to replace. I could hard wire something but then I lose the protection so looking for some help in figuring out what it may be.

Let me know what you think and thanks for the help.

 

[Sral]

Sounds reasonable
Personally, I think a Schottky less likely, but you never know. Maybe it’s just the chip supply running over it and the LEDs have a separate 24V.

You could open up to good lamp and have a look there. Maybe measure a Diode check of that part with a multimeter, if yours has that function. That could tell you if it’s a Diode or a fuse.

 

[bishoptf]

Sounds reasonable
Personally, I think a Schottky less likely, but you never know. Maybe it’s just the chip supply running over it and the LEDs have a separate 24V.

You could open up to good lamp and have a look there. Maybe measure a Diode check of that part with a multimeter, if yours has that function. That could tell you if it’s a Diode or a fuse.

I took some measurements with the diode measurements but not sure what I am really looking for. I got a reading in one direction of 2.2v but nothing in the other directions (reversing the leads). There was another diode that I tried the same thing and got a reading in both directions, like 2.7v and then .3v. I also tried to see if there was continuity and there isn't across the circuit. I have verified that if I jumper that chip the light works as before, I'm just not sure what it is to replace, lol.

I took a couple more pictures through my maginifier lupes, and underneath. I originally thought it was a resistor since that is what it looks like. It doesnt appear to look like a diode, its pretty thin.

 

[oreo54]

I took some measurements with the diode measurements but not sure what I am really looking for. I got a reading in one direction of 2.2v but nothing in the other directions (reversing the leads). There was another diode that I tried the same thing and got a reading in both directions, like 2.7v and then .3v. I also tried to see if there was continuity and there isn't across the circuit. I have verified that if I jumper that chip the light works as before, I'm just not sure what it is to replace, lol.

I took a couple more pictures through my maginifier lupes, and underneath. I originally thought it was a resistor since that is what it looks like. It doesnt appear to look like a diode, its pretty thin.

Hmm.. you have a good one don't you? Looks messy but aren't there some numbers on it?
My bets on a resistor or fuse..
Why not take out the what looks like a blown part from here?
It can be weird trying to check parts without removing them.

 

[bishoptf]

Hmm.. you have a good one don't you? Looks messy but aren't there some numbers on it?
My bets on a resistor or fuse..
Why not take out the what looks like a blown part from here?
It can be weird trying to check parts without removing them.

Yeah my plan is to pull one of the working ones and see if i can read any info off of it. This one I took an alcohol qtip to clean it and i think it took some coating off. It has a white bottom. I originally thought it was a resistor but I do not think so the more I look at it. It looks like a fuse but really hard to say. Would a fuse be damaged by reverse polarity. It appears whatever it is protected all the circuits and if I jump that one chip the lights turn on and act normal. I'm just trying to figure out what it is so I can replace it. Like I said going to pull a working one and take some pics and try to see if there is any writing on it.

 

[Sral]

Yeah my plan is to pull one of the working ones and see if i can read any info off of it. This one I took an alcohol qtip to clean it and i think it took some coating off. It has a white bottom. I originally thought it was a resistor but I do not think so the more I look at it. It looks like a fuse but really hard to say. Would a fuse be damaged by reverse polarity. It appears whatever it is protected all the circuits and if I jump that one chip the lights turn on and act normal. I'm just trying to figure out what it is so I can replace it. Like I said going to pull a working one and take some pics and try to see if there is any writing on it.

To be fair, white sounds like ceramic, like you would use in a fuse.

Circuits have protection diodes, so reverse polarity can create a kind of short behavior, which can probably trigger a fuse.

 

[bishoptf]

I just finished putting the light back together, been slow pulling the other working light and finally did that this morning. It seems to me to just be a 200ohm resistor, if someone disagrees with what is in the picture please let me know. I didn't have any 200Ohm resistors but I did have a 220 through hole and removed the one and put that one in as shown in the picture and it appears to be working as before. Again, if something doesn't sound right let me know, not sure how that resistor would have fried when I plugged it in reverse polarity but that appears to be the case, +24v runs through that normally to the daughter board with all the other stuff.

Problem 2 is I also messed up a couple of leds and when replacing it one of the pads came up. Never have lifted a pad but I guess there is always a first, pretty sure my iron was to hot etc. I wasn't sure how to correct it, it was on the positive side and I new I needed to bring that trace via a wire. I believe it needs to come from the one side of the resistor that sits above it and that is what I have done, appears to work normally now but would like some verification on that also, see the pictures that I annotated with where I did the wire.

 

[Sral]

200 doesn't necessarily mean it's a resistor and even if, not that it is 200 Ohms.

SMD resistors have a compressed coding scheme:
200 means 20 Ohms, 201 means 200 Ohms, etc.

You find the same on capacitors, even through hole ceramic ones show:
104 for 100 nF, 103 for 10 nF etc.

Might also be a 2 A fuse. Hard to tell, with my lack of experience.

 

[bishoptf]

200 doesn't necessarily mean it's a resistor and even if, not that it is 200 Ohms.

SMD resistors have a compressed coding scheme:
200 means 20 Ohms, 201 means 200 Ohms, etc.

You find the same on capacitors, even through hole ceramic ones show:
104 for 100 nF, 103 for 10 nF etc.

Might also be a 2 A fuse. Hard to tell, with my lack of experience.

Hmm, so I guess I am back to square one, it looks like a resistor and has a marker of 200 on it, lol. How do I go about figuring out what it actually is, funny seems to work fine with the 220Ohm resistor, lol. It's not in use, its a spare unit but I would like to get it working again.

I did come across this decipher for smd resistors - https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-smd-resistor-code which is what you were laying out above and converts to 20 Ohms. I guess I need to somehow figure out is it a resistor or a fuse.



@theatrus you have any insight in the above. I have a component that has 24v+ going through to sub board and trying to figure out if its a fuse or resistor. I reversed polarity and appeared to fry the chip and want to replace just not sure what to replace it with.

 

[bishoptf]

Went back and replaced the 220 Ohm resistor with a 20 Ohm resistor, still not sure how to tell if its a resistor but I am leaning towards that since the only marking is 200 and its pretty thin. Anyone else have any suggestions on figuring it out let me know and thanks for all the suggestions.

 

[bishoptf]

Welp it wasn't a 20 ohm resistor, turned it on and left it on and poof went the resistor and now appears to be in worse shape, lol. Will not power on so I guess I fried something else now...really wish I knew how to trouble shoot circuits and figure out what is bad since I have the ability to replace whatever is needed just no idea what needs replacing.

I did some continuity testing and the 2 connections both appear to go to ground, one is hardwired and the other had the fuse or resistor, my guess now maybe it was a fuse, lol. I've tried to figure out where 24v is coming into the board testing for continuity and at a loss to find where its coming into the board. I originally thought it was where the fuse/resistor was but that appears to test out to ground. Will keep poking at it, all the leds are fine its just something on the attached circuit board that is keeping it from working.

 

[geologeek]

is the part you have blown the one with 200 on it? as in is this the picture from a good unit?

its probably a PTC surface mount resettable fuse?

can you remove it and check its outline and see if it maches:

2018 Series PTC Surface Mount Resettable Fuse from China manufacturer - Yint Electronic

2018 Series PTC Surface Mount Resettable Fuse offered by China manufacturer Yint Electronic. Buy 2018 Series PTC Surface Mount Resettable Fuse directly with low price and high quality.

www.yint-electronic.com

as to what else you have blown......im afraid its a hunt down with the multimeter to see if any thing is not right, checking against a working unit and the broken one. But your problem is most likely in the vicinity of where you put the resistor.

If this is not the picture of the good unit, any chance you can get one of both and post together and we can try and hunt the problem.

 

[bishoptf]

is the part you have blown the one with 200 on it? as in is this the picture from a good unit?

its probably a PTC surface mount resettable fuse?

can you remove it and check its outline and see if it maches:

2018 Series PTC Surface Mount Resettable Fuse from China manufacturer - Yint Electronic

2018 Series PTC Surface Mount Resettable Fuse offered by China manufacturer Yint Electronic. Buy 2018 Series PTC Surface Mount Resettable Fuse directly with low price and high quality.

www.yint-electronic.com

as to what else you have blown......im afraid its a hunt down with the multimeter to see if any thing is not right, checking against a working unit and the broken one. But your problem is most likely in the vicinity of where you put the resistor.

If this is not the picture of the good unit, any chance you can get one of both and post together and we can try and hunt the problem.

Yeah it's possible that its something similar although it must not be re-settable since it did not reset, lol. When I pulled the one off it came apart in 2 pieces and the only other working one is on a unit that is in service and I cannot afford to mess it up, lol. I have been poking around with a multimeter and for the life of me cannot figure out where +24v comes into that daughter board. I originally thought it was where that fuse was but when I do continuity tests that pin and ground rings out. Something else fried on it for sure since I used to be able to plug in and all the leds would flicker but now only the small ones. However, I have tested the 3w led's and they all work so its in that control section. I tried replacing the resistor and they did not light up. I have the skill and tools to replace anything in that control section but not sure how to diagnose and figure out what is bad...

That picture in your post is of the working unit and the part that was bad was the one with the 200 on it since when I jumpered across it worked. Doing continuity tests on 24v+ and that control board I am unable to find where it comes into that board. I have tried to look at the traces but unable to figure it out.


I'd like to get it working again, all the leds are working just need to figure out the control board section. Appreciate any and all help...

 

[oreo54]

Believe these are the 2 voltage regulators..one 24v one 5 ( or 3.3)v

There's fans right? 24v?

 

[bishoptf]

Believe these are the 2 voltage regulators..one 24v one 5 ( or 3.3)v

There's fans right? 24v?

No fans it is a 24v input....in fact look below my resistor you will see on the board it calling out 24v. However right now plugged in I cannot find 24v coming into that control board.

 

[geologeek]

Problem 2 is I also messed up a couple of leds and when replacing it one of the pads came up. Never have lifted a pad but I guess there is always a first, pretty sure my iron was to hot etc. I wasn't sure how to correct it, it was on the positive side and I new I needed to bring that trace via a wire. I believe it needs to come from the one side of the resistor that sits above it and that is what I have done, appears to work normally now but would like some verification on that also, see the pictures that I annotated with where I did the wire.

Its hard to see with the white solder mask as to where the traces go, but if you are sure that is where the trace to the pad comes from then it is fine to connect to there. To be 100% you can scratch off the soldermask on the trace next to the pad and check for continuity back to the resistor.....then you are sure. Just add a bit of nail polish onto where you scraped and all is good.

 

[geologeek]

Not sure if this will be of any help but this is how i would go about tracking down the issue. I would also be checking the resistors/caps to see if any are open or way out of spec........but i believe it is a diode or few that have gone and can easily be replaced. if not the current or voltage regulators.........just pray it hasnt got to the "Brain"!

Given some of the datasheets below so you can look at typical applications and see how that pans out on your board.

fingers crossed for you buddy, but i am sure it is something easy.........just dont keep powering it up until you track the issue unless you have a bench supply and can limit the current! this may also be a good way to check for which chips are heating up by "injecting" current.


Hope you are back to happy reefing soon! Im off to battle the Dino's that suddenly appeared after 20yrs.........

 

[bishoptf]

Not sure if this will be of any help but this is how i would go about tracking down the issue. I would also be checking the resistors/caps to see if any are open or way out of spec........but i believe it is a diode or few that have gone and can easily be replaced. if not the current or voltage regulators.........just pray it hasnt got to the "Brain"!

Given some of the datasheets below so you can look at typical applications and see how that pans out on your board.

fingers crossed for you buddy, but i am sure it is something easy.........just dont keep powering it up until you track the issue unless you have a bench supply and can limit the current! this may also be a good way to check for which chips are heating up by "injecting" current.


Hope you are back to happy reefing soon! Im off to battle the Dino's that suddenly appeared after 20yrs.........

In your Top picture the blue squares I do not think those are diodes, I think they are just straight through pins. I'm still not sure where +24v comes into that board, I thought it was where the 200 fuse was but it has continuity with ground so unless something else is shorting not sure where positive power comes into that board. I will check the regulators but I made things worse with the 20 Ohm resistor and not sure what else needs to be replaced, lol.