Proliant MicroServer G8 – Red Alert

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Through this article I will share with you the bad experience I had with my Proliant Microserver G8 few days ago, concerning the blinking red-light problem on the front panel. If you are here, it is probably because you are encountering the same problem and I will reassure you: your server is probably not dead 😉 .

The symptoms are the following:

  • Instability of the server (inopportune reboot)
  • Sometime rebooting before the POST procedure to finish
  • Blue light on the front panel switch to a blinking red-light

Check your ILO log

Very simple step but it was not my first thought though. When you check the manual, Fast-flashing red (4 Hz/cycles per sec) = Power fault. Your first reflex was probably to remove all your hard disk, hoping it’s just a power supply problem. I was looking on many forums on the Internet, and some people have solved this issue… by changing their motherboard.

You have better chance to check the ILO log in fact. If you forget your ILO password, you can check this post. My log was specifying that a thermal power shutdown occurred. After disabling this protection feature in the Microserver’s BIOS, I noticed that it doesn’t solve the problem.

In ILO, I also noticed the thermal sensor n°1 (the one for the ambient temp.) was indicating 83°C or -1°C sometime.

temp_ilo_2Observing that the bottle of water on my desktop was not icing or boiling, I removed the faulty sensor from the case.


After that everything went back on rails. Fun fact about the status of the sensor I just removed, ILO still indicates that the status is OK. Also, if you wish to replace this sensor, it will cost you 35$! But don’t be fooled, the sensor is just a KN3904 NPN transistor that will cost you few cents.


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1 thought on “Proliant MicroServer G8 – Red Alert

  1. Thank you for the tip! I had written off my G8 and had relegated it to the shed. Sure enough, a dodgy sensor. You’ve made me very happy. Thanks again.

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