Dave Weaver, looks like a bad processor or logic board. here is what apple says:"
Computer begins to power up, the fan and hard drive are spinning, the power
LED is lit (or the LED goes off when button is no longer pressed), but there is
no startup chime or video
1. Reset the logic board. Refer to “Resetting the PMU on the Logic Board” in this
chapter.
2. Verify all PCI and AGP cards are seated properly.
3. Reseat the processor module.
4. Replace the processor module. Refer to "Before Replacing the Processor" in this
chapter.
5. Replace the logic board.
Let's see if this will help you out a bit more
Power Supply Verification
To power on, the computer’s logic board requires a “trickle” power of +5V. If the system fails to power on, first reset the PMU. Then follow the procedure outlined below to determine whether the problem is related to the power supply.
Note:
To verify the power supply, you need a volt meter. When connecting the volt meter leads to specific pins, make sure the power supply remains securely plugged into its connector on the logic board.
The following figure shows the pins and voltage on the computer’s power supply connector. (The color noted represents the color of the wire attached to the pin.)
1. Plug a known-good power cord into the computer. Do not turn on the computer.
2. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead of the volt meter to pin 14. The volt meter should measure approximately +25V. If you do not get a reading of +25V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +25V on pin 14, the power supply is likely OK. Go to the next step for further verification.
3. Check the trickle voltage by connecting the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead of the volt meter to pin 1. The volt meter should measure approximately +5V. If you do not get a reading of +5V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +5V on pin 1, the power supply is likely OK. Go to the next step for further verification.
4. Start up the computer by pressing the power button on the front panel. If the computer starts up normally, the power supply is OK. If the computer does not start up normally, go to the next step.
5. Check to see if the power supply fan is spinning. If the fan is not spinning, replace the power supply. If the fan is spinning, go to the next step.
6. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead of the volt meter to pin 24. The volt meter should measure approximately +12V. If you do not get a reading of +12V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +12V on pin 24, the power supply is likely OK. Go to the next step for further verification.
7. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 6. The volt meter should measure approximately +3.3V. If you do not get a reading of +3.3V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +3.3V on pin 6, the power supply is likely OK. Go to the next step for further verification.
8. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 3. The volt meter should measure approximately +5V. If you do not get a reading of +5V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +5V on pin 3, the power supply is likely OK. Go to the next step for further verification.
9. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 10. The volt meter should measure approximately +12V. If you do not get a reading of +12V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +12V on pin 10, the power supply is OK and the testing is complete. You have verified that the power supply is not the cause of the “no apparent power” symptom..
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