betapack not producing full output

[Mole239]

[posting on behalf of a technician with a broken computer...typical...]

 

At school we have an LD90 and 4 betapacks, one of which does not seem to be working properly, in that when the test button on the front is used the lights are noticeably below full brightness and when controlled through the 300 series desk a noticeable flicker occurs as the fader reaches 60. could this be a problem with the dimmer? or is it a problem with the supply to it?

[Dmills]

[posting on behalf of a technician with a broken computer...typical...]

 

At school we have an LD90 and 4 betapacks, one of which does not seem to be working properly, in that when the test button on the front is used the lights are noticeably below full brightness and when controlled through the 300 series desk a noticeable flicker occurs as the fader reaches 60. could this be a problem with the dimmer? or is it a problem with the supply to it?

 

Sounds like a dimmer fault to me, guessing a timing circuit issue.

 

If for example one of the diodes in the bridge arrangement producing the 100hz zero crossings fails open you would see this sort of weirdness.

Get the design technology or physics department to take a look there is normally someone in one of the other who understands how to drive a 'scope.

 

IIRC even the DMX version of this rack is really an analogue implementation with a trivial demux hung on the input.

 

Regards, Dan.

[peter]

Hi Simon

 

If you phone Keith Rogers on 01633 838088, he'll be able to talk you through the problem and if needs be arrange servicing of the unit.

 

 

Peter Kirkup

Zero88 Product Support

[MarcT]

The channel test button level can be set via a control - it does not necessarily bring the channel up to 100%.

 

Quoting from the Betapack 2 manual (found here ):

 

Channel Test Switches (Not Betapack 2 Plus)

Each channel has a push on/push off test switch. The

‘on’ level for all channels is set by the test level preset

which is above and to the right of the test switches.

A small screwdriver is required to adjust this control.

 

The "flicker" may be more of a worry. What sort of lantern is on the channel that flickers? If its something like a pinspot the flicker could be because there isn't enough load on the channel for the dimmer to operate smoothly. Try it with something >500W.

 

Also try setting another of your betabacks to the same DMX address & swap it into the DMX line at the same point, then test the equivalent channel at 60%.

 

DMX cabling problems can manifest themselves as flicker on channels - so check all the cabling and ensure only the last DMX device is terminated.

 

Regards,

Marc

[greateastern]

Hi,

 

I'm the person with the broken computer! Right to shed some more light. They are betpack 2s. I have had the plates on the front off and found some odd settings with a complete lack of standardisation between the 4 in terms of the test brightness which I have adjusted. Interestingly I found one of them was set to fade and the rest to hold (in case of a loss of DMX signal), the odd one out also has an analog control cable, I'm guessing there is a link there but oddly we seem to have no way of connecting an analog desk to the rig so I'm not sure what benefit the analog cable has or where it goes!

 

Having fiddled around and plugged and unplugged I have managed to elimiate the flicker on certain occassions only for it to be pack mid-performance I think therefore it must be a cable issue, especially since Betapack no 1 has also decided to flicker at certain times as well! But I cannot trace the fault as yet and am loathe to dismantle our control room to trace them all! Especially since I we are still (5 years on) getting our heads around the wiring and configuation of the hall as installed by stage electrics. We've never been happy but the school had stage electrics draw up a design and install it with no consulation of an independent expert or interested parties! [/rant]

 

Andy

[MarcT]

Ah!!!

 

There is a known firmware bug on some older betapacks when used in conjunction with some Strand desks (the GSX & LBX are known to be affected). Its possible the 300 series is also affected.

 

There used to be a support note on the Zero88 site about this, but I can't find it on the new site. However, courtesy of the "WayBack Machine" you can read the old article here:

Betapack 2 with Strand DMX

 

Check the serial numbers of your BetaPacks & contact Zero88 if they need updating.

 

I encountered this problem at the Edinburgh festival last year, when our GSX desk wouldn't talk to the venue BetaPacks - in my case causing a random flicker as if a chase was running, then total loss of control of the affected pack. Luckily we also had a demux with us & all packs had analogue in.

 

Out of interest, was everything working fine with a different desk before you got the 300, or was the whole lot installed together?

 

Let us know how you get on - if this is the issue it could help someone in the future.

 

Regards,

Marc

[greateastern]

The 300 series was installed with the rest of the rig, although we did have an older desk from the old hall... might dig that out sometime. Thanks for that tip btw I will have a look at the SNs and report back sometime in the week when I get a chnace to look!

 

Cheers,

 

Andy