Jester 48 way momentary unwanted blackouts

[alg]

We are running a show on Jester and have had two instances of complete blackout on stage for about 2 seconds about 6 days apart during performances. There were no Qs at the time the lights simply went out and came back on for no apparent reason. There was no apparent power failure and the desk & monitor stayed live. The dimmers are 5 x Betapack 3 and would hold their level if the DMX signal was lost, so it must a clear DMX level change from teh desk I would assume.

Is this simply an annoying hardware/software bug or something else, any ideas? This has never happened before in the 10 years we have had the desk. Could it be the current high temperatures and a chip on the way out? How feasible is it to find a fault like this?

[iank99]

You're right to suspect the ambient temperature - chipsets do have optimum operating ranges which can cause flakiness if those ranges are exceeded, the chips in a desk might feel they're running "hot" but they might be not far off their maximum ambient. From experience there's enough margin in the limits to allow some very hot running but it's measured in hours not days... The case being "sealed" won't help either in extreme ambient conditions because of the lack of air movement.

The other consideration might be - what else is "sharing" the power circuits that your desk is connected to? Again, being hot weather - all the old desk fans and air coolers come out of the cupboard to keep the humans cool (along with the ice makers and ice cream fridges running harder in a venue) - they can generate transient RF spikes and induce spikes on the mains. The spikes won't cause major issues but if for any reason the mains earth becomes "not zero" briefly (and it sometimes can by a few volts) then this might cause the DMX transceiver in the desk to hiccup - they use mains earth as 0v or tech earth so a clean noise free earth is essential, sometimes a supplementary earth from the socket supplying the desk direct to the main earth point (either the gas or water main) will clear this sort of issue BUT until this becomes a major issue for you i.e. it happens more frequently then it's probably not worth worrying about for now.

I wouldn't worry yet but can an eye on it to see if it happens more often over the coming weeks - it will also then be easier to diagnose if it is a fault on the mainboard developing.

 

[Edward Z88]

Hi alg,

On 7/23/2021 at 3:51 PM, alg said:

Is this simply an annoying hardware/software bug or something else, any ideas? This has never happened before in the 10 years we have had the desk. Could it be the current high temperatures and a chip on the way out? How feasible is it to find a fault like this?

I agree with Ian's comments above - it would be worth monitoring the issue, especially this week now it is cooler, to see if you encounter it again. If you do, drop us an email to support@zero88.com, and we'll be able to advise. If this is a hardware fault, the Jester would likely need to be sent in for service for a decent amount of time, to allow for replicating and then fixing the issue.

Many thanks @iank99 for your thoughts on potential heat or earthing issues.

Edward

[kgallen]

On 7/24/2021 at 10:16 AM, iank99 said:

sometimes a supplementary earth from the socket supplying the desk direct to the main earth point (either the gas or water main) will clear this sort of issue

 

9 hours ago, Edward- Z88 said:

Many thanks @iank99 for your thoughts on potential heat or earthing issues.

Yea, but don't go messing with your electrical installation eh. Main equipotential bonding should indeed be connecting metallic water and gas pipes to the MET but you don't want to be arbitrarily connecting your socket earths to any pipes. If your sockets supply equipment that has a high leakage or high functional earth current then there are proper methods defined in the IEE Wiring Regs for using multi-earth sockets (like MK Logic Plus "outboard" sockets). You need the advice of an appropriately knowledgeable electrician before you go here otherwise you could create a shock hazard or have tripping issues with RCDs.