Express Output Issue

[StradivariusBone]

I have an Express 48/96 that is outputting some odd data. It will essentially flash dimmers channels on and off at somewhat random intervals. Originally it was used to output directly to a Sensor Classic and we never noticed this, but in recent years we replaced the Express as the primary controller with LightFactory and began using the Express as an input wing of sorts using an ENTTEC dongle.

The problem is that when connected to LightFactory it will trigger random submasters on and off (LightFactory recognizes the DMX output as submaster input- which makes for a nice physical fader wing). I've replaced the optocoupler and communications chips on both port 1 and 2, but no change in the output was noticed.

Are there any other smoking guns with this console? The issue crops up the same in both outputs, so it isn't confined to that part. I thought the optocoupler might be the culprit, but no dice. I'm not sure I want to invest in sending the board in for repairs when I could just buy a cheapy DMX controller to use as a wing, but I'd like to fix the Express if possible since it is a good controller.

Here is a video of the issue-

https://goo.gl/photos/F2YdXzT9QF1g8irG9

For the video, I've got the board output going into a DMX Pro and then into a laptop running LightFactory displaying the DMX input window.

 

[jaightaylor]

Do you have RFU and Link plugged in?

 

[StradivariusBone]

Do you have RFU and Link plugged in?

Nope. Just one output line, testing in either port elicits the same results.

 

[Amiers]

Dirty faders?

 

[Mac Hosehead]

Have you tried adjusting the DMX output speed setting?

 

[BobHealey]

Does it do it with keypad captured channels, or just the faders? Do the on screen levels on the Express change when this happens? Other sources of RFI such as cell phones when this happens?

 

[derekleffew]

I'm not sure I want to invest in sending the board in for repairs ... but I'd like to fix the Express if possible since it is a good controller.

I'm wondering if it is really the Express and not the receiving software that's at fault. Can you try a different Express or Expression? Or connect the existing Express to a DMXter or other test device that has FlickerFinder™? Even connecting an LED fixture and watching for anomalies. Does changing the Express's DMX Speed make any difference? Have you asked ETC about the issue?

 

[StradivariusBone]

I'm wondering if it is really the Express and not the receiving software that's at fault. Can you try a different Express or Expression? Or connect the existing Express to a DMXter or other test device that has FlickerFinder™? Even connecting an LED fixture and watching for anomalies. Does changing the Express's DMX Speed make any difference? Have you asked ETC about the issue?

I've tried with two different DMX-Pro's and my first thought was that it was the dongle itself. I know of another venue locally that has a virtually identical setup, so it is possible with Express.

I did contact ENTTEC and ETC to do some troubleshooting on both sides. ENTTEC has two programs for test purposes, but both are somewhat clunky and they even told me that one of them may not be an accurate representation of the data on the line. However, LightFactory's DMX view is pretty accurate with what's actually happening when patched between the Express and the dimmers. When I talked to ETC (this was a while back) they thought it might be the opto chip causing the issues. We also tried adjusting the data speed on the Express and on LightFactory.

I'll try the LED to see, I don't have access to a DMXter unfortunately. I'm not sure how the Express is put together, but it seems like this error is coming from before the interface portion of the Express. This is only a guess though based on the fact that replacing the comm and opto chips did not change the output, I don't have the equipment to troubleshoot further in that direction.

At this point it's mostly a curiosity rather than a desperate issue. It would be nice to have it working, but it's not show-critical and can wait until we can afford a proper repair/replacement. The electronics hobbyist in me is curious though.

 

[lwinters630]

I had an express start acting like that and changed the power supply and it went away.

 

[RonHebbard]

I had an express start acting like that and changed the power supply and it went away.

I've heard many Express problems were rooted in their power supplies which, if memory serves, provided two or three different voltages.
Toodleoo!
Ron Hebbard.

 

[StradivariusBone]

The PSU is an interesting thought here. It is conceivable that this device has suffered some lightning damage and thinking back I did notice when I put my DMX tester (the little keychain that just has LED's on pins 2 and 3) it was very dimly lit. I thought that might be a product of the bad comm chips, but looking at it again it's still the same. The Express has two voltages +12V and +5V plus a couple of grounds. I'll have to try metering the PSU brick to see if it's giving the proper voltage.