Film-Tech Forum ARCHIVE: Static causes Mod IIB shutdown

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Posted by Randy Stankey (Member # 64) on 02-18-2009, 02:20 PM:

Smart Mod IIB cinema processor:

Just happened today.

Was running the program as normal. Just finished the trailers. The feature had been running about 2 minutes. Went to tweak the volume.

A static spark jumped from my finger to the chassis of the processor as I touched it. The spark caused the sound to go off. All the lights on the control card went dark but the level meters kept running.

It took me about a half minute to figure out what happened but I pressed the "Stereo" button and the sound came back on again. Every thing seems to be okay after that. The feature is running right now with no problems.

I have never had this happen with any processor before but I can see how it might occur. I've been lucky all these years, I guess. [Shrug]

The big question:

Is this in the range of normal behavior for this type of processor or am I seeing "end of life issues" beginning to occur?

If this is in the normal range of behavior then I'll just have to remember to be careful with static.

If this is a signal that the processor is coming to the end of its useful life then I'm going to have to work on getting it replaced very soon.

What do you all think?

Posted by Gordon McLeod (Member # 33) on 02-18-2009, 02:27 PM:

You were lucky that you didn't kill the cd 4508 logic chip on the format card as it is very static sensitive
No the processor is probably not at the end of its life I had the CP200 at cinesphere do that a lot too
But chips can only stand static abuse so long

Posted by Randy Stankey (Member # 64) on 02-18-2009, 04:44 PM:

Thanks, Gordon! [Smile]

Related question:

If this happens again and it kills the chips on the format card, will I be able to get replacements or repairs?

Smart has gone "Tango-Uniform."
I don't remember if any other company took over that line or not.

I can solder and replace parts if necessary but I don't have the knowledge to do component-level debugging and repairs. I assume that I will be on my own to find replacements or to find somebody to repair it.

Not only do we show movies, we present the Met Opera HD broadcasts from satellite. If this thing goes out, both of these programs could be dead in the water until we can figure things out.

What's the prognosis for getting repairs on this processor if something should happen to it?

Posted by Gordon McLeod (Member # 33) on 02-18-2009, 05:32 PM:

most of the chips are socketed so they are easy to change
SMART is still in business just a bit harder to deal with
the mod2b came with almost complete schematics so user repair as long as it is not the NR or matrix cards is easy
All that said a USL JSD80 would be a better choice in that venue now
BUT STATIC and all DSP devices are a NO NO
so I would get to the route of the static like probably ripping out the booth carpet and replacing it with either antistatic carpet or tile

Posted by Randy Stankey (Member # 64) on 02-18-2009, 07:44 PM:

There is no carpet in the booth. It is tile floor. But the booth is at the top of the balcony which is carpeted.

I was sitting in the last row of the balcony monitoring the show from there. This is only 10 feet from the booth door.
The booth is small, probably only 10 feet by 15 feet. Sitting inside that room with the projector running, it can be loud and uncomfortable. I let my students sit in the last two rows of the balcony with the booth door shut as long as they take turns checking the film after every reel change.
(That's what cue dots are for! Aren't they? To remind you to go check the projector. Right? [Wink]

)

Anyhow, I was sitting in the balcony. The trailers had just finished. I got up to go check the projector and tweak the volume, etc. The static must have built up when I was walking up the stairs to the booth. I am surprised that the charge didn't dissipate from walking across the tile floor. I wear rubber soled leather sneakers. Must have been enough charge left over by the time I got there... all of 10 feet across the floor.

I'll just have to remember to put one hand on the equipment rack BEFORE I touch any equipment inside.

Posted by Oscar Neundorfer (Member # 458) on 02-19-2009, 05:04 AM:

This actually was sort of common for the MOD IIB. It was somewhat sensitive to large static discharges to the volume control. Usually the only thing that happens is what you experienced, although if the discharge is severe enough, the 4508 IC could be damaged. The IC should still be readily available as far as I know, and I believe it is socketed, so changing it is very easy.

There is no indication of an end of life issue with what you described.

Posted by Randy Stankey (Member # 64) on 02-20-2009, 11:04 AM:

That's good to know. Thanks! [Smile]

I think I'm going to try to get my hands on one of those ICs, just in case. Even if the chances are small it's better to have one and not need it than the other way around.