Chapter Six - Maintenance81Chapter 6 - MaintenanceThe 3500 is designed to withstand the harsh environment of the factory floor.Routine maintenance can help keep your system in good operating condition.Preventive maintenance consists of several basic procedures that will greatly reducethe chance of system malfunction. Schedule preventive maintenance along with theregular equipment maintenance to minimize down time.Preventive MaintenanceHere are some preventive measures you can take:• Clean the monitor screen using a non-residue cleaner such as a mild windowcleaning solution or CRT screen cleaner. Take care not to scratch the screen face.• Clean or change the fan filter periodically to ensure that the air circulating in theunit is clean. Wash the filter with warm water and dish soap, and let it air dry. Do notscrub the filter, and do not re-install it into the unit until it is completely dry.• Base your maintenance schedule on the type of environment the system is in (i.e., ifthe area is dusty, you should schedule maintenance more often than if it is a dry,clean area). Check the filter often to determine if it needs to be changed ahead ofschedule.• Remove dust and dirt from PC components. If dust builds up on heat sinks andcircuitry, an obstruction of heat dissipation could cause the unit to malfunction. Ifdust reaches the electronic boards, a short circuit could occur.• Check the connections to I/O modules, especially in environments where shock couldloosen the connections. Check to see that all plugs, sockets, terminal strips, andmodule connections are solid.• Remove unnecessary articles, such as drawings or manuals, from the unit. They canobstruct air flow and create hot spots, which causes the system to malfunction.• Do not place noise-generating equipment near the 3510/3512.• Stock spare parts to minimize down time resulting from part failure. Spare partsstocked should be 10 percent of the number of each unit used. Main CPU cardsshould have one spare each. Each power supply should have a back up. Inapplications where immediate operation of a failed system is required, you may needto stock an entire spare computer module. Refer to the Spare Parts List in thischapter.• Replace the module with the correct type. If the new module solves the problem butthe failure reoccurs, check for inductive loads that may be generating voltage andcurrent spikes and may require external suppression.