Urgent help please

Charger

Apprentice elf
Joined
Nov 5, 2013
Messages
75
I attempted to turn on my big w string lights (3 strings from mfc originally) this morning. I had not tested them this year before then. About the first 20 come on, with every 2nd light in the next 10 very faint and then none work until about another 10 at half strength towards the end. I have had a quick look over but can't see any obvious issues. Just hoping someone may have some advice to diagnose the problem. Thanks.
 

David_AVD

Grandpa Elf
Community project designer
Generous elf
Joined
Jun 12, 2010
Messages
4,681
Location
Victoria Point (Brisbane)
All of the Big W (and other brands) lights will do this over time. Individual LEDs start to die and make sections of the string dim.

Finding the dud ones can be fun. Sometimes cutting the whole bad 2 metre section out of the string is the best way to continue using them.
 

i13

Dedicated elf
Joined
Jul 5, 2013
Messages
1,172
My guess would be that at some stage you applied a voltage that was too high and you've blown some of the LEDs. One blown LED causes an alternating section of 10 to go out with it.

My suggestion would be to use a lower voltage so that the lights come on dimly for testing. Try shorting across the wires to each LED by poking through the insulation with a sewing pin. The dud section will come back on when you happen to short across the blown LED. Once you've replaced the blown LEDs you can seal up the holes you poked in the wires using silicone or liquid electrical tape.

The reason for using a lower voltage while testing is that when you short across an LED, you remove it from the series section which means the others in line with it can die if you test with the light set at full brightness.

If you happen to be using a cheap power supply then I wouldn't trust it enough to poke through the wires while the light set is powered.

Of course don't do any of this unless you're using a low voltage light set.
 

Charger

Apprentice elf
Joined
Nov 5, 2013
Messages
75
Update.......Miracle result! While plugged in and looking through the set, I bumped a section with my knee. The lights all flashed on for a second. I then went through the area near where my knee hit and tapped each bulb. What do you know - when I put a bit of pressure on one particular bulb (from a set of 600) all lights worked perfectly. Thanks fellas for your suggestions.
 

Charger

Apprentice elf
Joined
Nov 5, 2013
Messages
75
Quite possibly David. Just happy they are working now. Just trying to sort several other issues now. It never ends.
 
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