LED ight string and Voltage Detector

[Rincewindwiz]

Hi All,

I have a broken LED light string (I've two actually, one embedded in an Xmas tree and one standalone) . It seems these are wired in series so I presume that one or more LEDs are U/S. The challenge is finding the broken LED(s) and then what to do with them.

I was prpposing to simply work down the string seeing where there stopped being a voltage (and asuming the immediately prior LED was broken). But that will be tedious. The LEDs contacts are wrapped in tape so I was thinking of a non-contact voltage detector.

Are there any cheap non-contact voltage detectors that will work with LEDs? I think this string has DC as there is a PCB with 4 diodes on it (looks a bit like a recitfie) at the start of the string r and I thought non-contact voltage detectors were a bit iffy with DC?.

Assuming I can find the LED, I guess I just replace it with similar or perhaps with a simple resistor (and ignore that light). What is the correct resistance?

Thanks for an thoughts

 

[Rincewindwiz]

THanks telectrix - its about where I thought I was going to get to. Since the greatest minds on the electricians forum cant come up with a better solution (other than the depressingly modern 'throw them away and get a new one').
Depressing really that modern technology cant do much better that we did 30 years ago.
Festive felicitations to all

 

[HandySparks]

... Since the greatest minds on the electricians forum cant come up with a better solution (other than the depressingly modern 'throw them away and get a new one')....

Didn't like my suggestion then?

 

[Rincewindwiz]

HandySparks
No - I agree with everything you said. I am just depressed that I shall have to resort to 1950s technology to fix a 2010 problem, I thought you bright sparks (no pun intended!) might have a better idea

I'd like to think the reference to Telectrix was sarcasm but actually I simply misassociated an author - not that I didn't appreciate his/her formula!

 

[efficiencyman]

I wonder if by 2050 the Chinese will come up with a fault code reader ? No it`s all a part of the big plan to make us spend more on a frequent basis. Well there goes another £50 on replacement, plus another £50 for landfill then there`s the waste carriers licence or bin men (rates) That`s not in our national benefit that add`s to our deficit.
I remember well the 1950`s 20v mes lamps, Oh they are so simple to fix ! I have only replaced a few lamps & resoldered a few screw in lampholders over the years. I have them working now, been faithful for nearly 60 years. I can`t say that for the Noma electronic controlled sets that have gone wrong the first year. Is that progress, for who ?
Having typed all this I do move with the times, have upgraded outside & in with LED fittings throughout which I highly recommend.

 

[telectrix]

nah. bring back acetylene lamps. good enough for geordie's car , so......

 

[PEG]

nah. bring back acetylene lamps. good enough for geordie's car , so......

...and how many times were you caned,for dropping carbide in the ink wells? :icon12:

 

[telectrix]

only once. second time wasa for connecting the bunsen burners to the cold water main