Supermicro H11SSL-I-O only heartbeat light, no system power light


Jun 15, 2016
For the post code? It was FF I think.

Also, what can I use to diagnose the CPUs? As we don't get "motherboard LED1" to turn on, so I don't know how we can get any diagnosis on the CPUs itself... or even the motherboard. Is there some part we can use? Surely there is another way to help debug this / rule things out.

Any ideas? As without motherboard power (LED1), we can't tell anything from IPMI right?
What is the status, Root.ed? Did you manage to make those motherboards running?


New Member
Sep 29, 2019
I have probably the same issue! Keep me up to date.
7502P - H12SSW (BIOS Code FF and no LED)


New Member
Sep 15, 2020
A related issue that may have a connection and result in confusion when troubleshooting the senarios above which I just ran into. I have a H11SSL which I had set up very bare bones (no power switch) which I had tested ok for reboot when power is restored. It runs Ubuntu. I needed to make a change to its mounting and shutdown from Ubuntu. After I had remounted the mobo it simply would not boot - no fan on PSU indicating that the motherboard was not signalling the PSU to turn on main power despite standby power and BMC LED being OK. Thanks to reading the above I plugged in another LAN cable for the IPMI and noticed a "Power On" button. Instant joy !!! I later discovered I had the BIOS setting "Restore on AC Power Loss" set to "Last State". My careful shutdown had set the state accordingly and the board dutifully failed to power on.


New Member
Nov 27, 2019
I thought I'd share my (vaguely) similar story as someone might find it useful.

I have a supermicro X11SCL which gave me a major headache at first because I couldn't get it to post/boot no matter what I did, no power-on led or other signs of life, but I could get access to IPMI just fine. After a very long series of tests I finally found the problem was the power supply. I had been using a slightly older top-brand 80+ silver PSU which turned out to be version ATX 2.2, and despite being physically and electrically identical (AFAIK) to the latest ATX 2.4 standard there can sometimes be strange issues with recent motherboards (apparently due to the way they utilise power slightly differently these days). Swapping it out for a brand new PSU solved the issues, so the morale of the story is, make sure your PSU is at least reasonably new before ruling it out as the cause, epesically if you test with a spare from an old build.

Hope that helps.
  • Like
Reactions: TXAG26 and Henry42