Conventional Fixtures Help! Why are my lights flickering?

[theisbr]

I did an install for my church back in March of this year. We installed a ETC Smartfade ML which runs to a DFD 125 EE splitter and out to 5 different locations in the space. I have received a complaint that some of the lights have started to flicker when other lights are being brought up. The issue only happens on one of the lines from the splitter. The line coming off the splitter controls 2 ETC Smartbar SB4-10, then an 11" ETC Selador Lustr, 2 more Smartbar SB4-10, and then a second Selador fixture. There are 4 ETC Source4 fixtures with 575w HPL lamps plugged into each of the Smartbars. The first Selador is displaying a little bit of flickering in one of the colors, and all the Source4 fixtures on the 3rd Smartbar are flickering. This is not being observed by any of the other fixtures.

I am headed out to the facility tomorrow to see if I can track down the problem. Any ideas on where I should start looking? It seems to me that the DMX signal is being corrupted, but there is another Smartbar and another Selador fixture further down the DMX line that are acting normally.

Any ideas would be helpful.

It should not matter but here is what is on the other DMX lines from the splitter (and no problems have been observed on these lines):

3 lines have three ADJ Ultra bars

the last line has 1 Smartbar SB4-10 in between two more Selador fixtures.

 

[Les]

Are you using any DMX terminators in the system? If not, I'd try adding one to the end of each chain first to see if that helps.

 

[theisbr]

That was going to be the first thing I checked, but I think I used terminators.

 

[JD]

Swap the splitter outputs. If the problems stays the same, you have eliminated everything upstream and know the problem is on that lone loop of cable and fixtures.

 

[theisbr]

I think I identified the issue. The issue seems to be in the cable run from the splitter to the gang box wall plate. I started at the last fixture in the DMX line and working backwards towards the wallplate and everytime I took a fixture off the line, the problem either changed or moved to the previous fixture. Unplugging the terminator caused the DMX signal to no longer be recognized by the Smartbars as shown by the DMX indicator blinking. Once once I opened up the wall plate, I saw that one of the signal lines in the DMX run was shorting out to the common. After redoing the termination, the fixtures worked as expected. Thanks for the help.