SSC troubleshooting

[mikedbom]

I originally posted about a memory config error when trying to read a chip I had just programmed. I reset the Pickit3 and that problem seems to be gone. However, I have an SSC that will not take a program with the SS Utilty. Pickit3 programming goes smooth but when I go to set the start channel, only the first light is a dim blue.

What I've done:
Tried a different string
Swapped big chip and small chip
Retouched all solder joints
Compared layout to known working SSC
tested for power in and out 12v
Tested for data <5 volts

I'm assuming based on my troubleshooting the problem is on the board and not a wiring or programming issue. Is the more testing I can do to figure this out?  Also have programmed other SSC's without issue. It's just this one.

[tbone321]

The first thing that I would lo at is to make sure that all of the transistors are in the correct positions.  Since they all look the same, it is easy to place them in the wrong position.  The next thing I would do is take a PIC out of a working unit and put it into this SSC.  If the replaced PIC works, then the issue may still be with the Pickit-3.

[mikedbom]

All transistors have been verified with correct part and direction. I swapped both chips out with known working...same result.

[tbone321]

Then the next step would be to replace the string with a known working one.

[mikedbom]

Lol. See my first post. Did that too.

Used a 128 pixel string. Programmed and tested with a different SSC successfully. Took the chips out and put them in the suspect board. Reprogrammed with pickit3 and tried to set start channel, no dice. I can only assume a part on the board is bad however aside from testing resistors, I'm not sure what to look for.

[keitha43]

How far from the ssc to the 1st node? That sounds like a symptom I saw when there was too much length between them. I saw it with the v2 ssc's. Had to shorten it to about 2 feet with the 3 pin connectors. The v3 ssc's seem to be able to do about 6 feet.

[mikedbom]

Standard pigtail. I have not added any length. So maybe a foot to 18 inches. This string also works great with other Ssc's.

[tbone321]

Sorry about that, I forgot the first post.  How are the strings being connected to the controller?  If you are using the waterproof connectors, make sure that the pins are connected to the correct ports and that the connector is good.  There have been some issues with wire colors being changed and some with breaks in the wires as well.

[mikedbom]

They are soldered straight to the board. No connectors. See my attached images for reference. I've also checked for power and layout compared to other strings.

[keitha43]

I am assuming this is a v4 ssc since I don't see any jumpers. I would reheat all solder points and make sure the solder goes all the way through the board. Then use a stiff brush on the bottom of the board to remove any solder spatter. Too bad there is not a test firmware for v4 yet.

[mikedbom]

Misread the post. I am using the waterproof connectors. Just checked continuity and the blue is broken somewhere. Holy crap. Thanks Tbone. I'll swap it out and try again. That has to be it though.

[mikedbom]

Problem solved. And to think brand new stuff would work and not cause problems. Thanks again for the stimulation.

[tbone321]

No problem, glad to see you get it working.