Run-in test system for PC circuit board

A run-in test system for microprocessor-based circuit boards, including:

• a test chamber for removably receiving a microprocessor-based circuit board unit under test (UUT);
• a heating system for heating a UUT in the test chamber;
• a cooling system for cooling a UUT in the test chamber;
• a display;
• memory for storing software, including:
• UUT-executable self-diagnostic software;
• and
• UUT-executable communication/diagnostic branch control
• software for causing the UUT to sequentially and repeatedly perform low temperature diagnostic, high temperature diagnostic and cycling temperature diagnostic test phases, including:
• low temperature diagnostic phase software for generating low temperature control commands and causing a UUT to execute the self-diagnostic software at a relatively low temperature during a relatively low temperature diagnostic phase;
• high temperature diagnostic phase software for generating high temperature control commands and causing a UUT to execute the self-diagnostic software at a relatively high temperature during a relatively high temperature diagnostic phase;
• and
• cycling temperature diagnostic phase software for generating low temperature control commands and high temperature control commands and causing the UUT to execute the self-diagnostic software at both the relatively low temperature and the relatively high temperature during a cycling temperature diagnostic phase;
• a variable power supply adapted for interconnection to the UUT;
• and
• a control system adapted for interconnection to the UUT and coupled to the power supply, heating system, cooling system and display, including:
• run-in test initiating means for causing the UUT to initiate the execution of the self-diagnostic software and the communication/diagnostic branch control software;
• cooling system control means for causing the cooling system to cool the UUTs to a first temperature in response to the low temperature control commands;
• heating system control means for causing the heating system to heat the UUTs to a second temperature greater than the first temperature in response to the high temperature control commands;
• power supply varying means for causing the power supply to vary the power supplied to the UUT during the diagnostic phases;
• diagnostic software monitoring means for monitoring the UUT execution of the self-diagnostic software during the diagnostic phases;
• and
• display control means for causing the display to provide an indication of a run-in test failure if the UUT fails to successfully complete the execution of the self-diagnostic software during the diagnostic phases.

A computer-readable storage medium programmed with communication/diagnostic branch control software for execution by a microprocessor-based circuit board unit under test (UUT), and adapted for use in connection with a microprocessor-based circuit board run-in test system of the type including a temperature control system, a display, memory for storing UUT-executable self-diagnostic software, watchdog timer means for timing watchdog periods and for causing the display to provide an indication of a run-in test failure if the UUT fails to properly execute the self-diagnostic software during the watchdog periods, and test cycle timing means for timing a test cycle and for causing the display to provide an indication of a successful run-in test if the UUT successfully executes the self-diagnostic software during the test cycle, wherein the communication/diagnostic branch control software includes:

• cold mode software means for causing the UUT to operate in a cold mode diagnostic phase, including means for causing the temperature control system to cool the UUT to a first temperature, means for causing the UUT to execute the self-diagnostic software, and means for activating the watchdog timer means;
• hot mode software means for causing the UUT to operate in a hot mode diagnostic phase, including means for causing the temperature control system to heat the UUT to a second temperature which is greater than the first temperature, means for causing the UUT to execute the self-diagnostic software, and means for activating the watchdog timer means;
• cycling mode software means for causing the UUT to operate in a cycling mode diagnostic phase, including means for causing the temperature control system to vary the temperature of the UUT between the first and second temperatures, means for causing the UUT to execute the self-diagnostic software, and means for activating the watchdog timer means;
• and
• test cycle mode means for causing the UUT to sequentially and repeatedly operate in the cold mode diagnostic phase, the hot mode diagnostic phase and the cycling mode diagnostic phase.