My cob light just fell over and then died, please help :/

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DreadCthulhu

Member
My brand new cob light was sitting upright on its side while I was letting it run to make sure everything was wired correctly. As I got my final of 4 lights finished I went to set it up and let it run and see how bright all 4 together are. One of the lights fell over and just died. It still won't turn on. I'm smoking atm so I don't freak out and then I going to check it out with a multimeter. Does anyone have any experience with this to know what might all be fucked? Any suggestions on what to check out or which part I might have broke from the impact would be greatly appreciated. Drivers are remote mounted, clu048-1212's in ideal holders.
 
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DreadCthulhu

Member
I can't even get good contact to the cobs with my multimeter to do a continuity check to make sure they still work. Any help on how to even troubleshoot this light with the ideal holders on would be great.
 
dstroy

dstroy

Well-Known Member
Use a pin to remove the wire from the ideal holder. There is a video on how to do that, then you can test continuity.
 
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DreadCthulhu

Member
dstroy said:
Use a pin to remove the wire from the ideal holder. There is a video on how to do that, then you can test continuity.
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Are the second holes smaller than the primary holes on the holder? I tried sticking my multimeter prongs in the second set of wire holes but it didnt do anything. I look for that video now, ty.
 
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DreadCthulhu

Member
dstroy said:
Use a pin to remove the wire from the ideal holder. There is a video on how to do that, then you can test continuity.
Click to expand...
I got the wires out, stuck the multimeter in the wire holes and it doesn't show anything just the default 1 it shows in continuity mode. Also tried connecting to the end of the two wires going into a cob from the other ends and still no reading at all.
 
nfhiggs

nfhiggs

Well-Known Member
DreadCthulhu said:
My brand new cob light was sitting upright on its side while I was letting it run to make sure everything was wired correctly. As I got my final of 4 lights finished I went to set it up and let it run and see how bright all 4 together are. One of the lights fell over and just died. It still won't turn on. I'm smoking atm so I don't freak out and then I going to check it out with a multimeter. Does anyone have any experience with this to know what might all be fucked? Any suggestions on what to check out or which part I might have broke from the impact would be greatly appreciated. Drivers are remote mounted, clu048-1212's in ideal holders.
Click to expand...
You can't really check cobs with a multimeter. It won't tell you anything useful.
 
dstroy

dstroy

Well-Known Member
DreadCthulhu said:
Any idea how to troubleshoot what's wrong then? Id at least like to know which cobs still work so if need be I can replace one or two instead of all 5.
Click to expand...
Does your multimeter have a diode test? You check the cob with that.

You should take them out of the holders and test them individually.

Inspect the holders carefully and check continuity between the pad and terminal.
 
The Dawg

The Dawg

Well-Known Member
Did You Put it Together? If So Check Each Wire by Pulling On Them. If All Are Tight Then My Guess Would Be That You Didn't Get A Holder Tight Enough So Go Back And Check Each By Taking It Apart And Redoing Them. :weed:
 
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DreadCthulhu

Member
dstroy said:
Does your multimeter have a diode test? You check the cob with that.

You should take them out of the holders and test them individually.

Inspect the holders carefully and check continuity between the pad and terminal.
Click to expand...
Apologies, after looking online I was saying continuity but it appears it's a diode mode, it's what I used to check my mars lights out before. The thermal grease stays liquidy so it'll come off still right?
 
nfhiggs

nfhiggs

Well-Known Member
dstroy said:
Does your multimeter have a diode test? You check the cob with that.


.
Click to expand...
Won't do any good. A cob does not read like a diode with a multimeter. It takes .7 volts to forward bias a single junction and Cobs have 10-25 junctions in series. That's 7 to 18 volts just to see a front to back ratio on it. A multimeter uses a little over .7 volts in its diode setting. Cobs will show open, good or bad with a meter - unless its shorted.

They will need to be removed and tested individually with an appropriate power source.

This is one reason I don't do series.
 
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DreadCthulhu

Member
The Dawg said:
Did You Put it Together? If So Check Each Wire by Pulling On Them. If All Are Tight Then My Guess Would Be That You Didn't Get A Holder Tight Enough So Go Back And Check Each By Taking It Apart And Redoing Them. :weed:
Click to expand...
I did, do I need to pull it all off or could I just make sure that all the screws are at 4.5 lb/in? Is it more likely that something is just loose rather than I broke a cob from the shock of the fall?
 
D

DreadCthulhu

Member
nfhiggs said:
Won't do any good. A cob does not read like a diode with a multimeter. It takes .7 volts to forward bias a single junction and Cobs have 10-25 junctions in series. That's 7 to 18 volts just to see a front to back ratio on it. A multimeter uses a little over .7 volts in its diode setting. Cobs will show open, good or bad with a meter - unless its shorted.

They will need to be removed and tested individually with an appropriate power source.

This is one reason I don't do series.
Click to expand...
What would testing with an appropriate power source entail? Find a 36v power cord and plug it directly into the holder? Or would I need the 7-18v?
 
nfhiggs

nfhiggs

Well-Known Member
DreadCthulhu said:
it didn't register anything when I attached them to the wires coming off the holders, maybe the holder isn't tight on after the fall.
36v each cob 180v in the series
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You'll need about 25 v across them to get them to glow dimly. I keep a cheap 24V power supply on hand for testing new COBs I get. They are available from Amazon for about 25 bucks.

If you are using solderless holders, most likely one of those came loose. COB's are relatively robust and should not be easily broken.
 
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DreadCthulhu

Member
nfhiggs said:
You'll need about 25 v across them to get them to glow dimly. I keep a cheap 24V power supply on hand for testing new COBs I get. They are available from Amazon for about 25 bucks.

If you are using solderless holders, most likely one of those came loose. COB's are relatively robust and should not be easily broken.
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That's good to know, I'll check those out. Thank god for Amazon.

I'll check that all the screws are at the 4.5lb/in and go from there. Thank you for your help, I really appreciate it. I wanted to cry when I saw my brand new light go out
 
dstroy

dstroy

Well-Known Member
nfhiggs said:
Won't do any good. A cob does not read like a diode with a multimeter. It takes .7 volts to forward bias a single junction and Cobs have 10-25 junctions in series. That's 7 to 18 volts just to see a front to back ratio on it. A multimeter uses a little over .7 volts in its diode setting. Cobs will show open, good or bad with a meter - unless its shorted.

They will need to be removed and tested individually with an appropriate power source.

This is one reason I don't do series.
Click to expand...
Can't you still check forward and reverse bias resistance?
 
nfhiggs

nfhiggs

Well-Known Member
DreadCthulhu said:
That's good to know, I'll check those out. Thank god for Amazon.

I'll check that all the screws are at the 4.5lb/in and go from there. Thank you for your help, I really appreciate it. I wanted to cry when I saw my brand new light go out
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I know the feeling. I've had shit like that happen.

This is the power supply I use:

https://www.amazon.com/Switching-Transformer-Regulated-Computer-Project/dp/B00ANFJ26U/ref=sr_1_3?ie=UTF8&qid=1493090970&sr=8-3&keywords=24+v+dc+power+supply

It has a little orange adjustment that goes from 18-31 volts. Handy little thing to have around.
 
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