How to fix Asrock c2750d4i with C2000 bug

[rayrayrayraydog]

As an update, I have finally gotten my board to POST successfully with the 5+2 (1 in my case w/ Rev 1.03) resistor installs as described in the servethehome forum: https://forums.servethehome.com/ind...tom-c2000-series-processors.13173/post-369313

It doesn't POST consistently and the Vcore, 1.0, 1.1 values will slowly drop over 15 minutes or so until the board locks up. Getting closer!

 

[kubosh]

Hi Guys,
Thank you for your input for this thread, it was very helpful. I started with resistor 100Ohm + 470 Ohms however mainboard had a problem to start.
Found on different forum about fix for Supermicro motherboards using 220Ohms resistor between PIN 1 and 5.
So far 7 mainboards fixed that way and are working well. Some of them need time to boot (about 30-60 seconds) but working without any problems.

 

[Ericloewe]

That's not a proper fix, merely a bodge to get the host to boot. It misses the second LPC clock, which is used by the BMC. The result is that the host can't communicate with the BMC and thus can't do IPMI maintenance (e.g. User management), is missing serial ports and Serial over LAN, etc. That is also what's causing the timeout on boot, as the system firmware tries repeatedly to initialize the peripherals on the BMC, until it gives up and continues without them.

I'm not sure if some of the more elaborate repairs on the ASRock boards deal with the second LPC clock, but it would be worth a second look.

 

[kubosh]

Maybe permanent fix is not possible due to nature of the problem. I have 7pcs of these motheboards and they had a problem to boot if I had two resistors since startup, when I turned on the system and then added resistors - mainboard booted fine. The option with 220Ohms resistor is not perfect however in my scenario always make mainboard to boot.

Have another system with Atom C2550 on Supermicro mainboard and to be honest I never used IPMI, once I booted TrueNas is working 24/7 so for people someone like me, the fix may be the solution for non working system.