White Lock Up??

[rdebolt]

I posted above, but thoght that this might be better.

I just received the rest of my nodes from Ray and have started the burn in process. I have 3 strings so far that will cycle through a couple of time then lock up in "white mode", well sort of. Not all of the nodes are pure white. I used the 150ohm resistor on all of my sscs and have tried different controllers on each string. My question is "How do you pin point which node is causing the issue when they lock up?" I am using 128 node strings and have not cut any of my last shipment up yet. Any suggestions?

Update to above.

I decided to quit fighting 128 nodes and decided to Run my mega tree with 32 strings of 64 nodes instead of 16 strings of 128 nodes. It appears to me that the larger number of nodes the more unstable they are. I had a tested string of 128 nodes that had been running through the test cycle fine for over 24 hours. I decided to start with it since I knew that it was a good string. After cutting it in half now it will run through 1 cycle red, green, blue, and then stop on white. This is a string that I just disconnected from power, counted nodes, cut and insultated the end wires. I tried another controller with the same results! Any ideas?

[jnealand]

Welcome to the insanity.  I still have several strings I am fighting with.  I am mostly fighting partial rainbow strings (almost always starting somewhere in the last 15 node).   It is really hard to tell which is the bad node when the color changes keeps starting in a different spot.  At least they do not lock up except for one string.  I do believe that shorter strings have fewer problems.  Most of my problem strings started as 128 nodes.

[dpitts]

Someone in the past posted a list of troubleshooting tips, one was for the white locked up problem.

You basically barely connect string to controller using three wire pigtail from Ray. You connect it just enough to power it then pull it slightly apart till lights are slightly connected. The trouble nodes seem to light very dim but not others. I used this technique to find a few bad nodes.

[mokeefe]

Someone in the past posted a list of troubleshooting tips, one was for the white locked up problem.

You basically barely connect string to controller using three wire pigtail from Ray. You connect it just enough to power it then pull it slightly apart till lights are slightly connected. The trouble nodes seem to light very dim but not others. I used this technique to find a few bad nodes.

I'm not sure I'm understanding what you are saying here. How do you "barely connect string to controller" and "pull it slightly apart till lights are slightly connected"?  I too am struggling with the white lockup and rainbow colors on many of my strings.  Perhaps a short video of your procedure  would be very informative.  Thanks.

-Mike

[rrowan]

I was guessing he met to pull on each node

Rick R.

[rdebolt]

What I am getting out of it is to slowly take apart the ssc from the string until resistance is high. I am nervous to try that because it sounds like letting the smoke out of an ssc to me, but maybe not.

[Corey872]

rdebolt - I don't think they want you to pull the controller apart at the electronic component level, just it's connection with the string...somewhat similar to putting an extension cord in the wall socket, then pulling it out until the lamp starts to dim and flicker.  Basically you're creating a high resistance connection with the thought that any node 'on the edge' of failing will not be able to respond and be set apart from the others.

As for my brief foray into troubleshooting:  If the whole string is doing something crazy, I'd suspect the very first node.  If you're getting rainbows at different locations, I'd note the point each rainbow starts over several color intervals.  Eventually you'll find a node which is the first bad actor (ie the node closest to the start of the string which doesn't make all the color changes).  Most likely it's the node just before that causing troubles.

On two of my bad strings, bending/flexing the suspect nodes revealed erratic operation.  You wouldn't think much would shift under that epoxy, but flexing was just enough to cause an issue...maybe a bad solder joint?  On at least one node, I can visually see the corner of the 1804 chip is cracked away.  The piece isn't in the epoxy, so must have happened during production.  But I suspect that leg of the chip may be faulty or not firmly soldered.   

If you put a few drops of baby oil or vegetable oil on the node, you can get a pretty clear look inside and may be able to visually spot an issue.  This isn't too practical with the whole string, but if you can narrow it down to a few nodes, it might help spot visual troubles before cutting.

[rdebolt]

Thanks for all of the help. I am slowly getting them all on line with the key word SLOWLY. Once I decided to cut the strings in half I am not having as many "rainbow" issues, but almost half of the the strings are having "white lock up" issues. I have about 4 stings that I have not been able to figure out yet, but I put them aside until I finish cutting and splicing all of my other strings. Work is really getting in the way!!!

BTW Great picture Corey872!