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| TROUBLESHOOTING & REPAIR |
PC BOARD TROUBLESHOOTING PROCEDURES
WARNING
ELECTRIC SHOCK can kill.
Have an electrician install and service this equipment. Turn the input power OFF at the fuse box before working on equipment. Do not touch electrically hot parts.
CAUTION: Sometimes machine failures appear to be due to PC board failures. These problems can sometimes be traced to poor electrical connections. To avoid problems when troubleshooting and replac- ing PC boards, please use the following procedure:
1.Determine to the best of your technical ability that the PC board is the most like- ly component causing the failure symp- tom.
2.Check for loose connections at the PC board to assure that the PC board is properly connected.
3.If the problem persists, replace the sus- pect PC board using standard practices to avoid static electrical damage and electrical shock. (Read the warning inside the static resistant bag.)
NOTE: It is desirable to have a spare (known good) PC board available for PC board troubleshooting.
4.Test the machine to determine if the fail- ure symptom has been corrected by the replacement PC board.
NOTE: Allow the machine to heat up so that all electrical components can reach their operating temperature.
5.Remove the replacement PC board and substitute it with the original PC board to recreate the original problem.
a.If the original problem does not reap- pear by substituting the original board, then the PC board was not the prob- lem. Continue to look for bad connec- tions in the control wiring harness, junction blocks, and terminal strips.
b.If the original problem is recreated by the substitution of the original board, then the PC board was the problem. Reinstall the replacement PC board and test the machine.
6.Always indicate that this procedure was followed when warranty reports are to be submitted.
NOTE: Following this procedure and writ- ing on the warranty report, “INSTALLED AND SWITCHED PC BOARDS TO VERIFY PROBLEM,” will help avoid denial of legiti- mate PC board warranty claims.