Optiplex 755 Flashing Amber Light - Processor Power Connector

Hi twd1987,

I’d suggest that you follow the steps mentioned below and check if the system switches ON.

1. Switch off the computer.
2. Disconnect the power cable from the wall.
3. Press and hold down the power button for 15 seconds.
4. Then connect back all the peripherals and check if the system switches ON.

If the system is able to boot up after performing the above steps then I would suggest that you run the diagnostics on the computer by following the steps mentioned below and check if there is any issue with the hardware on your system.

1. Turn on or restart the computer.
2. Immediately at the Dell logo screen, starting tapping the key once a second until the One Time Boot menu appears (if the computer boots to Windows turn the computer off and try again).
3. At the One Time Boot menu, press the arrow key to highlight Diagnostics, PSA+ or Enter ePSA, then press to begin the hardware Diagnostics.
4. Write down any error codes listed. Reply to us with the error codes.

Dell Optiplex 755 comes with diagnostic indicators. If the computer is not starting up you can refer to the diagnostic indicators.

Blinking Amber on optiplex 755 indicates ‘The power supply is receiving power from the source but is unable to properly distribute it to the components’. Also, I’d like to know the status of the diagnostic LEDs (1 2 3 4) which are located on the front of the chassis between the headphone and USB connectors, depending on the chassis.These diagnostic indicators are only active and visible during the POST process. Once the operating system starts to load, they turn off and are no longer visible.

I have dell optiplex 755 .i want to know the meanings of (1,2,3,4) while blinking amber on turning the computer on

Power supply is not working so 1 2 3 4 are not going to be lit.

I have same problem with optiplex 755 orange light blinking continuously but system is not starting i have done first steps you've told but still its not working. What should i do now ?

Flashing Amber power button is bad power supply.