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| Troubleshooting Without Diagnostics | |
Solving Power Supply Problems |
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| Solving Power Supply Problems |
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| Problem | Cause | Solution | ||
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| Power supply shuts down | Voltage selector switch | Select the proper AC voltage. | ||
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| intermittently. | on rear of computer |
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| chassis (some models) is |
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| not switched to correct |
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| line voltage. |
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| Power supply fault. | Replace the power supply. | ||
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| Computer powered off | Processor thermal | 1. | Ensure that the computer air | |
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| automatically and the | protection activated: |
| vents are not blocked and the | |
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| Power LED flashes Red two | A fan may be blocked |
| cooling fan is running. | |
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| times, once every second, | or not turning. | 2. | Open hood, press the power | |
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| followed by a two second | OR |
| button, and see if the processor | |
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| pause, and the computer |
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| The heatsink/fan |
| fan spins. If the processor fan is | ||
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| beeps two times. Beeps |
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| not spinning, make sure the | |||
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| continue for five iterations | assembly is not properly |
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| fan's cable is plugged onto the | |||
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| after which the LED flashes | attached to the |
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| system board header. Ensure | |||
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| will continue until the | processor. |
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| the fan is fully/properly seated | |||
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| problem is resolved. |
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| or installed. | ||
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| 3. If the fan is pugged in and | ||
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| seated but not spinning, replace | |
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| the processor fan. | |
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| 4. | Reseat processor heatsink and | |
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| verify that the fan assembly is | |
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| properly attached. | |
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| Power LED flashes Red, four | Power failure (power | 1. | Check that the voltage selector | |
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| times, once every second, | supply is overloaded). |
| (some models), is set to the | |
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| followed by a two second |
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| appropriate voltage. | |
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| pause, and the computer |
| 2. | Open the hood and ensure the | |
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| beeps four times. Beeps |
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| 4- or | ||
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| continue for five iterations |
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| is seated into the connector on | ||
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| after which the LED flashes |
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| the system board. | ||
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| will continue until the |
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| 3. Check if a device is causing the | |||
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| problem is resolved. |
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| problem by removing ALL | ||
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| attached devices. Power on the | |
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| system. If the system enters the | |
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| POST, then power off and | |
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| replace one device at a time | |
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| and repeat this procedure until | |
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| failure occurs. Replace the | |
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| device causing the failure. | |
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| Continue adding devices one at | |
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| a time to ensure all devices are | |
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| functioning properly. | |
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| 4. | Replace the power supply. | |
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| 5. Replace the system board. | ||
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Service Reference Guide, dc7600 |