Hi dualfree,
I will be glad to help you. The Inspiron 5150 comes with three types of indicators Power LED indicator, diagnostic LED indicator and Beep codes. This system can emit a series of beeps during start-up if the display cannot show errors or problems. These series of beeps, called beep codes, identify various problems. One possible beep code consists of repetitive three short beeps. Also let me know if there are any light indicators on the power button.
Also let me know what indicators you see on the computer by referring the below picture:
Image may be NSFW.
Clik here to view.
Do reply with your findings.
