How to Test Electronic Cards
- 1). Inspect each circuit board for burnt or broken components prior to performing any troubleshooting. Any board showing signs of corrosion should be replaced.
- 2). Swap out the suspect board with a known good one from a unit that works properly. If the problem goes away, the board was the culprit. It can be set aside for later repair.
- 3). Remove the board if it's held in place by an edge connector. Clean the plated contacts on the board with a cotton swab and alcohol. Set it aside to dry. Clean the connector with aerosol contact cleaner. After it evaporates, reassemble the unit and test it. If the board has ribbon connectors, remove the ribbons by pulling back the connector tabs with a pair of tweezers. Clean the ribbons with a swab and alcohol. Use the aerosol cleaner on the connector. Reassemble and test the unit.
- 4). Use the digital multimeter to check that the board has power if it still doesn't work after the above steps. The problem may lie in the power supply or the interconnecting wiring. If the board has simple DC outputs -- say, for lighting a series of lamps -- use the multimeter to see if any of the outputs work. If it's has an audio output, use the multimeter to see if there's an AC voltage.
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