Strip of Pixel Lights Has 5 Pixels Stuck On Red

JimB

New elf
Joined
Feb 20, 2020
Messages
14
Location
Highland, Michigan - U.S.
Have had my Megatree (16 Strips of 50 Pixels each) working for a few years now with no issues. Tonight I noticed that on one strip there are 5 pixels stuck on red (not all in a row). They do not change as the sequences plays out. Was working fine a couple days ago. Seems odd that if any pixels went bad that they would all be on one strip all of a sudden. Anyone have any ideas what the issue could be? Just noticed that none of the other lights on that strip are working, just the 5 stuck on red.
 
Last edited:

Indigogyre

Journeyman Elf
Generous elf
Joined
Jun 26, 2021
Messages
420
Swap the Bad strip with the port next to it to test to see if it's a connection to the strip issue or if there is something wrong with that one strip. I would advise not to hot swap them and just power everything off. reduces the risk of frying something. If it is bad maybe swap it for the strip at the end to at least keep the tree mostly up and running.
 

JimB

New elf
Joined
Feb 20, 2020
Messages
14
Location
Highland, Michigan - U.S.
Swap the Bad strip with the port next to it to test to see if it's a connection to the strip issue or if there is something wrong with that one strip. I would advise not to hot swap them and just power everything off. reduces the risk of frying something. If it is bad maybe swap it for the strip at the end to at least keep the tree mostly up and running.
Thank you for the reply. Just came in from swapping the port to strip 11 that is working to strip 6 that is not working. Strip number 6 still didn't work. I did notice that the first light at the bottom of strip 6 was dimly lit and flickering. Do you know if there are any good articles on how to determine which pixel might be bad or would I just assume that since the first one doesn't light up properly that it is the first pixel? Thanks again for the reply.
 

merryoncherry

Senior elf
Generous elf
Joined
Apr 2, 2022
Messages
633
Location
Cherry St., Hudson MA USA
I use the idea that was passed to me - get rid of the first one that isn't working properly but also the one before it, in case the problem is with power or data being sent from the prior pixel.
 

Indigogyre

Journeyman Elf
Generous elf
Joined
Jun 26, 2021
Messages
420
Generally the pixels will go bad in order. It might be possible to use some pin probes to inject, power and data after the first led to see if the rest of the strip responds properly. all my experience is with the first pixel going bad and no longer pushing either power or data along the chain properly. I used to wire my own in the past and had issue so I switched to buying premade ones in the length I needed.
 

Skymaster

Crazy elf
Global moderator
Generous elf
Joined
Dec 19, 2021
Messages
1,042
Location
Western Sydney
I concur with @merryoncherry - The last working and the first dead are the two to be replaced. So far in all but one pixel I've replaced, it's been the last-working one that fails to send on data.
 

JimB

New elf
Joined
Feb 20, 2020
Messages
14
Location
Highland, Michigan - U.S.
Thank you for the reply. Just came in from swapping the port to strip 11 that is working to strip 6 that is not working. Strip number 6 still didn't work. I did notice that the first light at the bottom of strip 6 was dimly lit and flickering. Do you know if there are any good articles on how to determine which pixel might be bad or would I just assume that since the first one doesn't light up properly that it is the first pixel? Thanks again for the reply.
Finally got a chance in the daylight to diagnose my problem. Checked the power coming out of the port attached to the strip of pixels and it was 5 VDC. Then checked voltage going into the first pixel and found it to be 0 VDC. Replaced that cable and everything worked. Upon rolling up the bad cable I found that the positive lead of the ribbon cable was cut about midway. It looked just like it was cut with a pair of snips. Very strange. Don't know how that happened or when it happened.
 
Top