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How to Run a Power Supply Unit Self-Test On a Dell Desktop or All-in-One Computer

Summary: Learn how to run a self-test diagnostic on the power supply unit of a Dell desktop or all-in-one computer. Built-in Self Test (BIST) helps determine if the power supply unit is working. ...

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Instructions

Dell Inspiron, XPS, OptiPlex, Precision, and Vostro desktops include a power supply with a built-in self-test (BIST) feature that helps check the power supply unit health (PSU). The LED indicator on the power supply unit helps identify if it is faulty.

If the power supply unit does not deliver sufficient power that your computer needs, it will not turn on.

NOTE: Certain older models of Dell Inspiron, XPS, and Vostro desktops may not be equipped with a PSU built-in self-test. Learn How to Troubleshoot and Fix Power Issues.

Some causes for a power supply unit failure are:

  • The power cable is faulty or damaged.
  • The power outlet is not working.
  • The power strip or surge protector is faulty.
  • The power supply unit is faulty.

How to identify if my Dell desktop has a power supply unit with built-in self-test?

The power supply built-in self-test is found on the back panel of the desktop, next to the power cable connector (on some smaller chassis types, you may be required to remove the computer cover to see the BIST on the side of the PSU).

Examples of a power supply unit with the built-in self-test button

BIST button on the power supply of a desktop
Figure 1: Example of a BIST button on the power supply of a desktop computer.

BIST button on the power supply of a desktop
Figure 2: Second example of a BIST button on the power supply of a desktop computer.

BIST button on the power supply of a desktop
Figure 3: Third example of a BIST button on the power supply of a desktop computer.

BIST button on the power supply of a desktop
Figure 4: Fourth example of a BIST button on the power supply of a desktop computer.

Examples of a power supply unit without the built-in self-test button

power supply without the BIST button
Figure 5: Example of a power supply without the BIST button.


How to use the built-in self-test to diagnose power supply issues?

How to run self-test using the button on the PSU

  1. Turn off the computer.
  2. Press the BIST button and verify if the LED turns on.
  3. The LED must be solid and not flickering or flashing. The power supply fan turns on. If the PSU fan does not spin correctly, consider the built-in self-test as failed even if the LED lights up.
    1. If the BIST LED turns on, the power supply is delivering power to the computer.
    2. If the BIST LED does not turn on or the PSU fan does not spin correctly, the power supply is not delivering power to the computer. Disconnect and reconnect the power cable to computer and try again. If the BIST LED does not turn on, contact Dell Technical Support for repair options.

How to run self-test without the button on the PSU

  1. Turn off the computer.
  2. Disconnect the power cable from the PSU, and wait for 15 to 20 seconds.
  3. After 15 to 20 seconds, connect the power cable to the computer.
  4. The LED light turns on for 3 seconds and then turns off.
    1. If the BIST LED turns on, the power supply is delivering power to the computer.
    2. If the BIST LED does not turn on or the PSU fan does not spin correctly, the power supply is not delivering power to the computer. Disconnect and reconnect the power cable to computer and try again. If the BIST LED does not turn on, contact Dell Technical Support for repair options.

Additional Information

Affected Products

Alienware, Inspiron, Legacy Desktop Models, OptiPlex, Vostro, XPS, G Series, Fixed Workstations
Article Properties
Article Number: 000125179
Article Type: How To
Last Modified: 21 Aug 2024
Version:  10
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