Strand MX - D54 Issue

[Ian der Laan]

Hi,

 

I'm currently dusting down an old D54 desk to try and control a few act 6 dimmers (via D54 - Strand DeMux - Dimmer). The problem I'm finding is that the channels don't seem to corrilate to the dimmer channels. The fixtures are powering up but in the wrong order and wrong intensity. I have cleared all memories and done all of the user tests. On the face of it, everything works (bar the lack of a memory card).

 

I have tested the rig with an old Strand Action(!!) - also D54 - and that works fine.

 

Any ideas?

[boatman]

It sounds as though the D54 output is faulty. If you have access to an oscilloscope you can display the waveform on it by using a TV sync. You can access Mk. 1 of the D54 specification on the Strand Archive here. I suspect the sync levels are probably down below the 5V required for correct operation.

[Ian der Laan]

It sounds as though the D54 output is faulty. If you have access to an oscilloscope you can display the waveform on it by using a TV sync. You can access Mk. 1 of the D54 specification on the Strand Archive here. I suspect the sync levels are probably down below the 5V required for correct operation.

 

 

Thanks for the reply.:)

 

I have no immediate access to an oscilloscope but may be able to ask around.

 

I will have a look at the wiring on the D54 out and see if there's anything obvious. I suspect I will find that it is below 5V as the lights never come on 100%, theyre always dim (is that a valid conclusion?)...

 

Other than dry joints/obvious faults, it there anything else I could check (with a multimeter)...

 

Thanks again.

[Kazeja]

If you are taking the back off, check the condition of the Nicad and replace if the ends have gone dull or furry.

 

The D54 has a low value series output resistor. Can't remember the value but should be easy enough to trace from the tracks. Check the value with your meter. If it's gone high, this could cause the symptoms you're experiencing.

 

K

[matt_beal]

Presumably you've checked the soft patch is 1:1?

[Ian der Laan]

Thanks for the replies.

 

Matt- Yeah, the soft patch is 1 : 1, I've cleared all of the memories. When I checked earlier, I hadn't confirmed the delete scene command, that's why I thought the dimmer channels were mixed up.http://www.blue-room.org.uk/public/style_emoticons/default/redface.gif The channels do actually now match up but the intensity still is really low and the grand master isn't doing anything at all.

 

I tested the output resistor @ 5ohms which is ok and there's continuity on the D54 socket to the board/resistor.

 

Now... what I did discover as I was giving up was that the power supply was rated at DC15V 350mA didn't say 'Strand' on it. I checked the manual and the PSU should be DC15V 800mA - could this be the problem?

[Kazeja]

One thing you may want to try is running the on board diagnostics to check the faders and voltages.

 

K

[Ian der Laan]

I ran the fader test but it was % based. Is there a separate voltage diagnostic?

[Kazeja]

I ran the fader test but it was % based. Is there a separate voltage diagnostic?

Can't remember off hand. You'll need to go through them in sequence.

K

[Ian der Laan]

Yeah, I did all of the user tests earlier. Everything seemed fine.

[Kazeja]

Few more things to try and narrow down the cause.

Is the D54 scalling factor set to 100%.

Do you have any DMX devices to hand to check the DMX output on the desk? Does it also have an upper limit like D54?

Are the "Patch Levels" 100%?

 

K

[Ian der Laan]

Thanks for the continued efforts. :)

 

 

 

The scaling is set to 100%, if you increase it (to max120%), the fixture levels respond accordingly.

 

I have an s72 demux I can test the DMX with (good idea).

 

 

All patch levels are set @100%

 

 

I'll let you know how I get on with the s72 - after this coffee!

 

Thanks again.

----------------------------------------------------------------------------------------------------------------

 

 

 

 

 

OK, I tested it with the s72 (DMX512).

 

The problem remains with the intensity (although I can raise the level to 200 in the patch - that makes the fixtures slightly brighter).

 

Also, the channels are mixed up - DMX channel 1 operates dimmer 1 but DMX2 operates a multitude of dimmer channels and cancels out channel 1 (it is definitely set to 1:1).

 

[Krislights]

From memory.. It's a bit like an M24.. there was a resistor on the power board you had to dick around with until the output was 5V. It maybe the same situation on the action desks.(similar things, from memory) R11. Something to do with your multimeter. Many years ago, when I was still a kid, I tried connecting DMX devices directly to a D54 signal, and got very similar results to what you are getting. Are you sure you have the right Dmux? D54 is pin1 Ground, pin 2 n/a and pin 3 signal... Floating earth? Also bear in mind inputs for acts are (-10v??) mini 2 was -15v, permus could be anything, -10 or -12v. and those stupid TXX modules/MXX on lumps of paxolin could also be changed from -10v to -12v. What was the interface last used with? Good luck.. I'll rack my brain during today for you, and see If I can't think of anything. K.

[Ian der Laan]

Thanks Kris,

 

It's the MX I'm having 'fun' with (the action works perfectly other than a few lost knobs/fader caps etc!).

 

I've tried both DMX (s72 demux) and D54(old strand demux which works with the action) and got similar results- low intensity but the channels were more mixed up with the DMX.

 

The d54 output resistor was @5ohms (which is correct according to it's rings).

 

Aghh!

 

Ps- the s72 is set to -10v.

[scjb]

Did you get anywhere trying a higher capacity power supply?

 

ETA: Strand Archive seems to imply that it was only the early MX's that used a 15V 800mA PSU, with later units being 18V at 800mA. What model MX is it?