SVC on Twitter    SVC on Facebook    SVC on LinkedIn

Related Articles

Keep the Learning Burning

Jul 12, 2010 3:47 PM, By Bennett Liles

On the front line in AV’s toughest environment.


   Follow us on Twitter    

Students take part in a business management class in the Capstone classroom of the Clayton State University School of Business in Atlanta. The room is Extron control equipped and has a dome-mounted camera, DVD recorders, and wireless microphones to conduct senior-level courses. Floor pockets provide AC and Internet while allowing tables to be rearranged.

Nowhere do AV systems have more direct impact on the lives of more people than American colleges and universities. Hundreds of thousands of projectors, video displays, media players, and document cameras convey a daily deluge of information directly to students. The campus AV plant is a dynamic machine—a media engine with spinning disks, flashing emitters, burning lamps, and lots of amateur operators.

The campus AV technician’s mantra is minimizing class time lost to malfunctions and operator error in an environment where each room system may be run for 10 hours or more per day by dozens of different operators—most of whom, while highly educated, have had no formal training in AV technology. Classes, club meetings, and special events make maintenance access to each room very tight, and it requires that the AV tech have an up-to-the-minute schedule for each classroom, conference room, and auditorium that can be searched by day, time, room, and user.

Clayton State University has a student body of 6,000 with 101 AV-equipped rooms and one technician—that’s me. I’m the AV guy with the tweaker and the flashlight. Current remodeling and renovation will soon bring that number to 107.

The university has come a long way in AV in the past eight years. In 2002, when I arrived, there was not a single projector-equipped classroom on the campus. Now all the classrooms have permanently mounted projectors, and a mix of 71 classrooms, conference rooms, and auditoriums have AV control systems—most of which I have installed between semesters.

Being the sole AV tech person for such a campus requires a special method of operation. I often liken my job to having 101 plates spinning on sticks. You can’t let too many go wobbling or there will be broken plates everywhere, so careful planning and prevention is the key to staying on top of it. I take every opportunity, usually between semesters, during spring break, and sometimes when I’m just passing by an empty classroom, to perform a quick check—particularly in those rooms the schedule show to be the busiest. A quick check involves cleaning the projector’s air filter (which clogs fastest in carpeted rooms), checking the VGA cable for bent pins, hooking up a handheld AV test generator to the PC connections, spinning a DVD in the player, and sliding a color print onto the document camera. All these checks can be done in around 4 minutes if performed in the right order and if I don’t need a ladder to get to the projector. As I go through each room, I check off each task from a pre-printed form that I made and I enter any maintenance items from this into an Excel workbook with a separate tabbed worksheet for each room. Longer-term maintenance projects such as changing control systems or doing any rewiring are planned for the day after classes end each semester.

At the center of the campus AV network is the technician’s control workstation. The center monitor runs the usual office applications, and it is flanked by monitors for Extron’s Global Configurator and GlobalViewer Enterprise software, which monitors and controls the AV resources in 75 classrooms spread across three campuses.

Installation vs. Maintenance

The three primary points of failure in classroom AV systems are VGA connectors, infrared buds attached to media players, and projector lamps. There is an entirely different mindset between AV installers and AV maintenance techs, particularly when one technician is time-stretched to keep such a large plant running, on how these items should be maintained. When the Clayton State University center and its 22 AV-equipped rooms first entered service in 2004, I went through the nice, neat contractor wiring of each podium and conference table and cut all but one of the tie-wraps around the VGA cables that connect to user PCs. I have to replace several VGA cables per week because the pins get bent out of alignment from the wear of being connected to and disconnected from instructor laptops dozens of times per day. Having only a single tie-wrap dramatically cuts down on the time needed to swap out the cables—much of which occurs either during classes or in the brief break between. In those situations, I have to operate in similar fashion to a NASCAR pit crew getting into the podium, fixing the problem, locking the access doors, and getting out of the way. Fortunately, the podiums need no fuel or tires. In rooms with no podium, such as biology labs, a short VGA cable running through the wall and up to the projectors is fastened and tie wrapped onto the end so that when the connector is damaged, only the short piece is replaced rather than having to thread an new cable all the way up to the ceiling.

The same free-cable method applies to power cords for media players. These are mostly consumer-grade VCR/DVD players, and there’s no trying to quickly fix them in the classroom. Instead, I swap out the problem unit with one from our backup inventory. For quick replacement, the power cables are kept tie-wrap-free. In some cases, where the podium requires fishing the power cable down through several compartments, I’ve made up 5ft. AC extensions for the media player so they can be AC-connected in the same podium compartment where they sit, with little clutter. A far better solution would be for them to have their own standardized AC connections right on the chassis. This would result in a lot less discarded copper when the units have to be retired. Other than malfunctions, the most common trouble with IR-linked media players is the IR extender buds getting knocked off. The adhesive they come with is not suited for the more challenging and robust academic environment, so I use plumber’s glue to attach them to the face of the player. It provides a sturdy seal, and the bud can still be removed with a firm pinch and twist without damaging the face of the player.

Depending on the model, when projector lamps reach a certain number of hours, special attention is directed at those rooms, and at the first sign or report of a lamp dimming, I take action to avoid a lamp failing during a class. Occasionally, projectors have other problems and have to be replaced on short notice, which means I have to be on my toes should a projector need to be switched out. Many integrators like to thread the cables down through a mounting pipe and through the mount to provide a better-looking installation, and this does have the desired effect, but when a projector has to be changed rapidly, having cables strung through the mount slows things down and sometimes requires the projector to be held with one hand while the cables are freed with the other, all while the AV tech is standing on a ladder. To avoid this, I have drilled separate holes through the ceiling tiles near the mounting pipes and run bundled cables so that there is no contact between the cables and the mount. In some rooms, the cables are run down the outside of the black mounting pipe and secured to it with black tie wraps. Of course, I keep situations requiring projector swaps to a minimum by inspecting all classroom systems during breaks between semesters. The typical tools used on these checks are a handheld video pattern and tone generator, an AC inductive sensor, a test DVD, a printed color test pattern for the document cameras, and a can of compressed air for the projector filters.



Acceptable Use Policy
blog comments powered by Disqus

Browse Back Issues
BROWSE ISSUES
  December 2014 Sound & Video Contractor Cover November 2014 Sound & Video Contractor Cover October 2014 Sound & Video Contractor Cover September 2014 Sound & Video Contractor Cover August 2014 Sound & Video Contractor Cover July 2014 Sound & Video Contractor Cover  
December 2014 November 2014 October 2014 September 2014 August 2014 July 2014