Mac 250 intermittent problem

[knightdan65]

Hi,

 

My two Mac 250 kryptons have developed a habit of intermitttntly cutting out - they still respond to pan/tilt and I can see the lamps are on through the slits in the covering, but there is no light output (and yes, the shutters are open). There are no error messages being displayed and I’ve checked that they are set for 230v at 50hz. It seems to me that this is an overheating issue, so I’ve been switching them off and allowing them to cool before resuming use and so far this has remedied the problem. But obviously this is far from ideal. Do I need to pull em apart and clean/replace the fans? Or does this sound like a more sinister issue? Any advice gratefully received

[DrV]

Umm. If the lamp is on and the shutters are open then some light WILL come out of the front. Do you perhaps mean you have commanded the shutters to open but they are staying shut?

[knightdan65]

Yes, sorry I should’ve been clearer. I command the shutters to open but no light is emitted. I could not see from the box whether they actually were open or not. This began happening during a dress run today so wasn’t able to take a closer look

[indyld]

Shutter AND Dimmer are set to open?

[knightdan65]

Yup

[indyld]

OK, so if you have definitely ruled out programming/control foul ups, just make sure that the fixtures aren't set to some stupid setting where they auto-blackout when you try to do something like move them or change colour too. A factory reset to defaults is a good way to clear out random silly settings in the depths of the menus.

 

If the issue is that the shutters themselves are intermittently getting stuck shut, it could be physical (heat distortion and sticking), it could be intermittent motors or a problem with the control. You'll need them on the bench to properly check them out and a poke around inside will give some clues as to what the problem might be. If you can't work out if/why the shutters are sticking with them powered off, then try running them with the covers off (and lamp off) while controlling them from a desk. Obviously, if the problem is due to heat then it may not be apparent all the time.

 

I recall that Mac250s had issues with heat dissipation and in the old days we'd leave the shutters open on the whole rig during breaks to reduce issues with sticking shutters particularly on the Mac range at the time. If you think that the fans should work and the blades are clean with vents, filters, airways unobstructed etc. then ask yourself if you think they are coming on when they should and at the right speed. There will probably be a thermo sensor system that might need looking into if not.

 

Edit to add: When you say switching them off to allow them to cool, I assume you mean shutting the lamp off. De-powering the fixture and cutting power to the fan isn't gonna be great for the fixture or the lamp in the long term either.

[Nicktaylor]

It might be both have fault of some sort that is causing the unit to go to black, the theory being you don't want to see the half colour or what ever is the fault so it shuts the shutter. In theory I would expect to see an error message of some sort. My comment probably doesn't add much to other comments!

[DrV]

<br />It might be both have fault of some sort that is causing the unit to go to black, the theory being you don't want to see the half colour or what ever is the fault so it shuts the shutter. In theory I would expect to see an error message of some sort. My comment probably doesn't add much to other comments!<br />

<br /><br /><br />

Actually it is spot on - from the troubleshooting section in the manual

Shutter closes suddenly.

 

The color wheel, gobo wheel, or a

gobo has lost its index position and the

fixture is resetting the effect.

 

There is a setting in the UTIL menu called FEBA. If you set this OFF the unit doesn't close the shutter when it detects such a problem. You would then be able to see what the problem was (misaligned color wheel or gobo).

Typical causes are a bad connection on a hall effect sensor (this is a very likely one), a mis-positioned hall effect sensor (too far from the magnet) or a wheel that has moved a little on its shaft.

[knightdan65]

Eeesh, looks like Monday is gonna be a long day with toolbox and a manual. Thanks for your thoughts. To be honest, though I understand much of what you’re all saying, I’m a little reticent to go poking about inside having not serviced movers before (especially as they belong to work, not myself). To that end, does anyone know of any people who could service and repair these things somewhere near Oxford?