Specifications

11. Check power supply output. Disconnect the diagnostic power cable from the power supply connector,
and measure power at the power supply connector by touching the black probe to the ground pin, and
using the red probe to measure power at the pins indicated in thegraphic below. Did you measure +12v
at each point? If yes, continue with the next step. If no, replace the power supply.
12. Check the main logic board voltages. Measure for +12v DC at capacitors C187 and C197 (identified in
graphic below). Ground the black probe to the logic board screw next to the battery, and touch the red
probe to the positive node at capacitor C187, and then at capacitor C197. Do you measure +12v? If
yes, go on to the next step. If no, replace the logic board.
13. Replace power supply.
14. Replace the logic board.
15. Replace the inverter board.
16. Replace neck assembly.
16 - iMac (Flat Panel) Troubleshooting
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