Intel® Desktop Boards
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Intel DX79SI - No Boot - No Video


Hi, I have a DX79SI board with Intel i7-3930K CPU. I get no video and cannot get to the BIOS screen. It seems I'm stuck at an unsuccessful POST for all components.


  • The beep codes I heard are consistent with a memory issue so I replaced my RAM, same issue.
  • The Board Status LEDs I see (If I'm counting and mapping them to letters correctly) are:
    • K (Watch Dog Fire/Back to BIOS) - This is flashing.
    • L (+5 V standby power indicator) - This is red
    • M (CPU Error) - This is red
  • I have also replaced the i7-3930K chip for an i7-3970K chip because of the CPU error chip I see and thinking that it' s not getting getting to the BIOS potentially because of a CPU failure. It's still exhibiting the same behavior.
  • I've seen similar posts with a recommendation to perform a BIOS recovery. I've tried that, still the same behavior.
  • For the video, I've also tried a different graphics card to rule that out, same behavior.

So, now I'm wondering if the motherboard itself needs to be replaced?


Any assistance would be greatly appreciated. I uploaded a still picture and short iPhone motion picture video showing the board status LEDs.

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6 Replies
Super User Retired Employee

Have you tried using a different power supply? We've seen a number of similar issues that were corrected by PSU change.

If that doesn't work, can you capture and upload the BIOS POST code sequence?



Thanks Scott, really appreciate the quick response. I just tried a different power supply and immediately got some beeping during POST. Unfortunately, that was quickly followed by some frying noise and some smoking so I think I'm on to at least a new motherboard...perhaps a new build.

I'm not sure what happened there, I've been turning this thing on and off repeatedly without any components burning like that. The PSU I had in the system was 850W whereas all I had laying around was a 650W...not sure if that caused it or maybe not hooking all the fans back up.



Super User Retired Employee

A 650W PSU should have been ok for this test. If it was insufficient, I would expect it to simply not work; I wouldn't expect this to cause any damage. Where are you seeing damage? Can you send closeup picture of that part of the board?

Let's be careful to be realistic here. This board was built 10 years ago. I can see capacitors (especially) getting brittle after this amount of time. 10 years is beyond the MTBF for many components on this board.



Agree, I was thinking the lower wattage PSU would've just not worked vs causing any issue. Per your 10 years comment, I just abandoned this issue and am refreshing most of the components. I realized how old the tech is and how difficult it would be to get support so decided to go with the LGA 2066 chipset (New board, new CPU, RAM, etc.) while keeping my case, graphics cards, and existing hard/SSD drives.


I'm not sure if you have the ability to close this thread, but I'm considering this closed.


By the way, I was super thrilled to see this support forum providing assistance even for products that have been discontinued. Please keep it up!

Super User Retired Employee

Actually, Intel Customer Support is not even monitoring this forum. There are two volunteers, myself and Al Hill, who are handling all of the Desktop Board issues. We're both retirees; myself from Intel and Al from MS. I was a part of the Intel Desktop Boards organization from its inception to its shutdown (and subsequent morph into the NUC organization). While I was also involved in standards, software and firmware projects outside of the organization, I was there and in some way involved in the release of every Desktop Board generation.


Community Manager

Many thanks to @n_scott_pearson for assisting in this peer-to-peer only forum since we discontinued board support a few years back. What would we do without you, Scott?!


And yes, @JustReal , I'll go ahead and lock this thread from further comments. If there are new questions, just create a new post. But as Scott mentioned, this forum isn't monitored by Intel agents, it's just for peer-to-peer help since we discontinued the products around 10 years ago. Kind regards,

Mary T.

Support Community Manager