express 24/48 no dmx output

It sounds like a bad output chip on the DMX 1 port.

There is no opto-isolator circuit on Express, the chip functions as the "fuse".  The DMX 1&2 ports and the RFU port all use the same chip.

Since it's a free-be, I'd suggest removing the brick - I.E. the back electronics section and swapping chips to see if that is the problem.  Pay VERY close attention to how the brick gets removed as it's a *** getting it back on.

If it's a bad chip, an ETC dealer can get a replacement, or if you are not planning on using an RFU or port 2, then use that chip instead..

Steve B.

It sounds like a bad output chip on the DMX 1 port.

There is no opto-isolator circuit on Express, the chip functions as the "fuse".  The DMX 1&2 ports and the RFU port all use the same chip.

Since it's a free-be, I'd suggest removing the brick - I.E. the back electronics section and swapping chips to see if that is the problem.  Pay VERY close attention to how the brick gets removed as it's a *** getting it back on.

If it's a bad chip, an ETC dealer can get a replacement, or if you are not planning on using an RFU or port 2, then use that chip instead..

Steve B.

Good luck with it and don't forget to call ETC Tech Support if you can't get it working or run into trouble.

Steve B.

Steve Bailey:

If it's a bad chip, an ETC dealer can get a replacement, or if you are not planning on using an RFU or port 2, then use that chip instead..

It's a bad idea to use one of the the RFU chips as a replacement for the DMX outputs.  Even if you're not using the RFU, removing one of the transceivers can cause the console to misbehave (you'd get phantom key hits because a logic line is left floating). You also probably don't want to steal the one from port B, since that can be a backup if you have future problems and may come in handy even if you don't. 

Basically; it's a cheap part, get a new one and save yourself from future headaches.

"It's a bad idea to use one of the the RFU chips as a replacement for the DMX outputs.  Even if you're not using the RFU, removing one of the transceivers can cause the console to misbehave (you'd get phantom key hits because a logic line is left floating). You also probably don't want to steal the one from port B, since that can be a backup if you have future problems and may come in handy even if you don't"

Some good advice.  My "knowledge" of all this was from my End User class, and as I recall and as it was taught to me, using an RFU chip OR the port B chip was IN CASE you needed both ports, or both DMX ports were fried AND you did not have time to get a chip in a hurry.  

Swapping the Port B to Port A to ascertain if the chip is bad is a first step.  Then get a new chip.  

Or, and a result of this being a freebie console and the user probably not wanting to spend money, the Port B chip will work if you don't ever need the port to function.

 Steve B.

i haven't had a chance to fiddle with it yet what with the evils of panto that we all face at this time of year...

 if it's a cheap part i'll just buy a few and keep some as spares, i wont be using the deak much to be honest, i normally use the pearl all day every day for it's sheer excellence in buskability but for some shows the express is legendary because it is a proper theatre stack desk.. it's such a shame that programming chases is so fiddly. i remember in the old days i used to program each step in a chase as a scene then use a subroutine to cyle round the steps... HAPPY TIMES

thanks for the help folks 

DMX chips are around 80p to a pound from most semiconductor suppliers.

In the UK, the best are probably CPC/Farnell and RS Components (if you need several), but Maplin are great if you only need one!

- The Farnell trade counter is in Leeds, and they'll take anybody's money. (Even late at night - I remember buying some bits at just after midnight once)