Trouble with a 27-channel DMX LED driver board

[Steven]

Someone reading this must have used one of those ubiquitous 27-channel DMX RGB LED controller boards. I use one at the top of my pixel tree for the 6-RGB-channel star. It worked last year, but I failed to test it this year before all the branches were up, making it impossible to access.

It's running what seems to be a test pattern, which leads me to my question:

Do these boards run a test pattern whenever there is no DMX signal? If that's the case perhaps the fact that I'm using a different E682 board could be the cause. (Maybe the new board isn't sending DMX.) I'll test this tomorrow when there is light, but I wanted to ask the question here just to make sure the answer isn't that I accidentally hit a DIP switch on the board, and that I won't be able to fix it without taking the tree down.

[k6ccc]

I believe some of them do run a test pattern if there is no DMX signal received.

[Ebuechner]

There are a set of 10 switches you must of hit number 10 to the on position that sets it in test mode. 1 through 9 sets the start DMX channel. Sorry for the bad news. I have the same board and doesn't go into test pattern if it doesn't have a DMX signal. The DIP switch number 10 must be in the on position for it to go into test pattern.

Edited November 14, 2015 by Ebuechner

[Steven]

It's unlikely that I accidentally moved switch 10, because the board is well shielded in a box, so I'm going to assume the problem is that my new 682 board is not sending a proper DMX signal. I'll test that tomorrow.

[Ebuechner]

Could your 682 board be sending a test pattern out on at DMX universe?

[Steven]

Could your 682 board be sending a test pattern out on at DMX universe?

Unlikely, since the test pattern continues when the 27-channel board is unplugged from the 682 board.

[Ebuechner]

I just tested my board. DMX connected rapid flashing on the status light no test pattern. DMX disconnected from the board status light goes solid still no test pattern. Turn on DIP switch number 10 get test pattern with DMX disconnected. Each channel turns on a color and moves to the next. Runs all the channels through red then green then blue and repeat. DIP switch 10 still in the ON position plugin DMX, test pattern goes away and the computer has control of the board again status light goes back to rapid blinking. So if your board is running a test pattern you have switch 10 in the on position and it is not getting a DMX signal. So hopefully the problem is down at your 682 board where you can get at it. At least some good news I thought if the switch 10 was in the ON position he would stay in test pattern regardless of DMX signal.

Edited November 16, 2015 by Ebuechner

[Steven]

So if your board is running a test pattern you have switch 10 in the on position and it is not getting a DMX signal. So hopefully the problem is down at your 682 board where you can get at it. At least some good news I thought if the switch 10 was in the ON position he would stay in test pattern regardless of DMX signal.

Thanks! This is very helpful, and tells me that I should be able to fix the problem from the ground.

[Steven]

I am somewhat embarrassed, but I found the problem. One of the chips on the E682 board was installed backwards. After reinstalling it correctly, everything works.

[Ebuechner]

I am somewhat embarrassed, but I found the problem. One of the chips on the E682 board was installed backwards. After reinstalling it correctly, everything works.

Yaaaay. Lucky it didn't burn the chip out. I was curious if you ever got it resolved.