dead MFC and removing it on 2 wire string

uppitt

uppitt

Apprentice elf
Joined
Dec 21, 2010
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Hi everyone,

I’ve been a long time member but haven’t posted for a few years. My display is mostly store bought lights in a static display so I rarely do any modding or go more advanced. Most of my lights have a MFC. I usually put the MFC in a zip lock bag to help keep water out, but I kinda forgot to do this on a few strings this year and after the down pour in Sydney last Friday a found a couple of large strings died where I know the PSU & string is good (coz I’ve swapped them out), but it’s definitely the MFC that has died.

A string of 1000 LEDs that has an MFC, is the same MFC mentioned in this thread -> https://auschristmaslighting.com/threads/dm-k1-6-bypass-replace.8218/

After the rain when this string was turned on, only half the LEDs were lit, and were flashing very quickly, strobe like. I gave the MFC a shake and realised there was likely water in it but then the string stopped completely (I should have disconnected the power before doing that...doh). So now that string is dead, and this morning I had a spare string and I cut and swapped out the MFC (the 1000 string was wrapped around trees and I really didn’t want to unwrap and re-wrap so it was faster to cut and replace the MFC. That string is working again, but I still effectively have a dead string (actually more than one like this).

Firstly, any chance anyone would know what component potentially may have died given the description I gave of half lit and flashing very quickly before fully stopping completely?

Secondly I’m happy to remove the MFC entirely if that is possible. Can I follow the suggestion for MFC removal given this is a 2 wire string -> "Total MFC Removal” in this wiki post -> https://auschristmaslighting.com/wiki/Bypassing_Multi_Function_Controllers#Total_MFC_Removal

The PSU is 31V, and these strings I bought I guess 4 years ago.

I was reading/watching some of BigClives stuff as well here:


View: https://www.youtube.com/watch?v=HaBLM5fOZBI


I'm not sure if what Clive did there would work on my 2 wire string that is a 31V string.

Thanks
Tim
 

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actually I think since posting I've realised that if I did remove the MFC I'd end up with only half the LEDs working due to the other half reversed polarity. So I guess to have all 1000 working again I need a working MFC, is that correct?
 
There's a couple of options. One is to computer control the string with a 2-wire controller from Hanson Electronics. Another is to drive the string with 24V AC, though you may notice some flicker.
 
What are the specs of the plugpack/controller that you removed? I have 16 that I pulled off icicle lights here. They were strings of 500 and 31V. I can't remember what wattage they were marked with. You're welcome to a couple for the cost of postage if the wattage is a match or alternately I have lots of DMX2-18 in stock and a few 31V power supplies.
 
hey thanks for the replies. I don't mind a little flicker. A little flicker or none, either is preferential. I included a photo of the plugpack, but it's :

Model: JT-DC31V12W
31V (DC) 12W

The controller is DM-K1.6

To be honest I've not looked yet at doing something with removing the MFC and running them off another controller. I've got roughly a 50/50 mix of 2 wire and 3 wire MFCs.
 
just started some reading on the controller you mention, I think that's something I will seriously consider for next year. Going around and pushing the MFC buttons everywhere is a pita.
 
AAH said:
What are the specs of the plugpack/controller that you removed? I have 16 that I pulled off icicle lights here. They were strings of 500 and 31V. I can't remember what wattage they were marked with. You're welcome to a couple for the cost of postage if the wattage is a match or alternately I have lots of DMX2-18 in stock and a few 31V power supplies.
Click to expand...

but if I can get my hands on some 31V MFC, that would be great to at least fix a few of these strings that have had the MFC die on me. I really need to do a stock take and categorising what voltage each of my strings are. Most are 31V (older BigW 3 wire and newer 2 wire). But I'm fairly sure I have some 24V stuff too, but off the top of my head that's mostly candy canes. I have close to 100 of them.
 
I'm honestly surprised no-one has a 24v 120hz power supply

would be perfect to fix all the 2 wire strings... anyone got a fairly durable frequency doubler/tripler?
 
basically that's all I'd be after, I'll look into the Arduino suggestion.. maybe I could run a few of them around the place

for the first year I might just run them 60hz 30hz and irritate the neighbours :)
 
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