My First DIY LED

Tim Fox

Well-Known Member
the latest light build I helped work on for @Humanrob had a simular issue, they wouldnt light up, diagnostics persued and you can check with humanrob but it boiled down to one of the cobholders not being seated and then the whole strand was dark because of series wiring, one issue in the strand/series shuts the whole light down
 

robincnn

Well-Known Member
Some people just have bad luck. My circuits never use to work first time i power them.
But it is easy to fix bad luck. I bought a multimeter. Its magical powers debug most electrical issues that can cause frustration.:wall:
Edit: prior to multimeter i use to debug circuit with a hammer but it never worked well :(
 
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SSJGemini

Well-Known Member
The first couple COBs I put on, I put a little to much thermal compound on. A bit leaked through. Is that a problem?
 

robincnn

Well-Known Member
Yes make the light work this week. You are making the RIU look bad... just kidding:mrgreen:

Thermal compound not eletrically conductive so should not be the issue.

+ of driver connects to + of first cob
- of driver connect to - of last cob
cobs connect to each other like - to + or + to -

For led or cob series, i connect multimeter to driver to check voltage first to test driver dc o/p
then i connect - of multimeter to driver - then put + of multimeter at cobs terminals one by one starting with cov nearest to + of driver to see where circuit is breaking. Caution freeky high DC voltage
 
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littlejacob

Well-Known Member
Nah......as long as it isn't touching the LES [the yellow egg] or leading to a wire short, you should be fine....I hit-off with Isopropyl on a Qtip.....You can wipe the LES with a clean Qtip and Isopropyl too fyi....
:peace:
Bonjour
i just realise that isopropyl alcool is called 90ºalcool in France and it is not allowed to sell some...cause tramps (bums? I am not sure of the word!)...peoples who live in the streets drink it...
So internet is my friend
HHave a great day ★
 

PurpleBuz

Well-Known Member
Thermal compound not eletrically conductive so should not be the issue.
some thermal paste is electrically conductive. e.g. arctic silver. I use Arctic's ceramique which is not electrically conductive.

The first couple COBs I put on, I put a little to much thermal compound on. A bit leaked through. Is that a problem?
like others mentioned the leak is probably not an issue, but it is possible that you have too thick of a layer, which is not optimal. goal is the thinnest layer possible.
 

BigYellowCob

Well-Known Member
like others mentioned the leak is probably not an issue, but it is possible that you have too thick of a layer, which is not optimal. goal is the thinnest layer possible.
If one was to error with either too much or not enough thermal paste, I think you're better to err on the side of too much paste. I've never heard of a cob frying because they had too much paste - I have seen a couple cases where cobs fried because of too little paste resulting in an air pocket behind the cob.
When installing my Veros, I added what I though was a good amount of paste to the back of the cob and carefully pressed it into the heat sink, then removed it, and found that 1/3 of the cob backing didn't have any paste on it. After seeing that, I spread paste on the back of the cob and some on the heat sink too, then pressed it down and checked it again and the coverage was much more uniform. Then I screwed it down and cleaned up any paste that may have oozed out with alcohol.
 

littlejacob

Well-Known Member
Bonjour
I applied mine with a blade and it was very nice and easy...it was my first time with TIM, so I put a very very thin layer on the cob and same on the hs!
Is it a problem if I didn't remove what was on cob sides (tim on hs)?
CU
 

brettsog

Well-Known Member
Bonjour
I applied mine with a blade and it was very nice and easy...it was my first time with TIM, so I put a very very thin layer on the cob and same on the hs!
Is it a problem if I didn't remove what was on cob sides (tim on hs)?
CU
No. You should see the mess they make in factory with thermal compound. I fix a lot of consoles and sometimes it's allover chip and mothrrboard and is a pain to get off of the heatsink.
 

alesh

Well-Known Member
Bonjour
i just realise that isopropyl alcool is called 90ºalcool in France and it is not allowed to sell some...cause tramps (bums? I am not sure of the word!)...peoples who live in the streets drink it...
So internet is my friend
HHave a great day ★
I knew French liked wine but this? You sure? About 20g of IPA is the lethal dose for human and it doesn't cause similar effects as a̶l̶c̶o̶h̶o̶l̶ ethanol. It just makes one sick.
 
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robincnn

Well-Known Member
I think @littlejacob is confused between iso propyl alcohol C3H7OH and denatured ethanol C2H5OH

Ethanol is what we drink to party. Most commercial non lab use pure ethanol is denatured with other bittering agents to make it unfit for drinking.

No need to denature IPA or iso proyl alcohol. It already unfit to drink.

@alesh looks like your likes are in audit. i tried to like your post and i got a popup.
Are you sure you want to like this post?

On their website it looks like all their thermal paste are not electrically conductive. Just checked artic silver 5 and artic alumina. They do say artic silver 5 is slightly capacitive
some thermal paste is electrically conductive. e.g. arctic silver. I use Arctic's ceramique which is not electrically conductive.
 
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littlejacob

Well-Known Member
Bonjour
No I talk about another 90º alcool...the
one they use to sell in pharmacy now they only have 70º one not 90º anymore...
I have denatured ethanol at 90º the one we use to light bbq and I know I can use it to clean things...but it is ok with cob?
Is there only ipa who work with cob?
Have a great day ★
 

littlejacob

Well-Known Member
Bonjour
Thanks I ordered some 90% ipa on the net...
I went in 3 electronic shop in Nice a "big"(small compare to US ones)city close to mine...and when I ask for ipa they looked at me like was an alien...!
Internet is your friend...and some says that TOR made the impossible...possible...but it is another story...!
Have a great day ★
 
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