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DZ68BC constant reboot, OC not working and external graphics V-Sync problems


First, sorry for any mistakes I'll make, english is not my native language.

My full spec:

Intel DZ68BC

Intel Core i5 2500K (no OC)

Patriot Viper Xtreme DDR3 2x4Gb

Gainward GTX 570 GS GLH (no OC)

FSP Everest 80 Plus 700W

Windows 7 x64 Home Premium (newly installed and clean)

This is my new motherboard and I have issues with it.

First of all, I did a BIOS update. Not sure if this bad or not, since I use Sandy CPU.

With 0042 system stucks on startup with Eb POST-code and goes to constant reboot.

With 0039 it shows warning message that tells my CPU is not supported, but jumps over it and load OS. OC not working.

With 0035 everything works well, no warning messages. OC not working again. BIOS shows wrong CPU frequency (5.9Ghz) as default and changing OC options for CPU or RAM has no effect. When I try to check my RAM speed with any special software it shows 560-660Mhz which is ridiculous.

So, since I can't roll back to 0028 I would like to use 0042 since it's last version with most problems solved. But for me it just doesn't work. What's up, Intel?

I gonna try 0036 and 0037 later.

Ok, let's imagine that I'll keep work with 0039 for example.

Here I experienced another problem. V-Sync.

You know, annoying horisontal displacements of picture in the middle of display? This is it.

And it's everywhere, not only in games. It's also right in OS interface, I can clearly see it while scrolling pages in browser, etc. Feels weird.

And during games I can't get rid of it, no matter if V-Sync is turned ON or not - no effect!

My display works with 60Hz refresh rate, if it matters.

I think it's motherboard fault. With my old MB everything worked fine, and I'm 100% sure in my GPU. This problem appeared right after MB replacement.

I tried different versions of nVidia drivers, I also tried different versions of MB drivers - from CD which came with it, then newer one from Intel site, and ended up with DriverPack Solution package. No difference.

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6 Replies

Hello sadpanda:

Thank you for contacting Intel Communities.

I would like to know if you have performed a BIOS recovery on your board.

This would be to the latest BIOS version: 0042 at 12/4/2015

Some useful links: Download BIOS Update [BCZ6810H.86A] Desktop Boards — Instructions for Recovery BIOS Update


Esteban C


This is first thing I did, I installed board and performed update from 0028 to 0042. Now I think it was a mistake, a big one. This gave me constant reboot with "Eb" post-code.

Then I performed recovery to 0039, this gave me warning message that my CPU is unsupported. Despite this fact, OS is loading. Overall work is unstable, ethernet adapter stops working sometimes, etc. Also, seems like OC settings does not apply.

Then I performed recovery to 0035, warning message disappeared. Not sure about OC settings again.

Another updating to 0042 gave me same issue as at first try.

And with all those BIOSes I've got that sync problem I described. Feels like you playing game with disabled V-Sync, but this effect is even in OS interface. And in games V-sync enabling/disabling haven't changed anything, seems like it's not working at all.

At this moment I switched back to my old board. Not happy about that actually.


Hello sadpanda:

Thank you for the information provided.

I would like to provide you with some recommendations when updating your BIOS to the latest version.

1. Perform a recovery to the last known version that was working properly (0035 would be my recommendation).

2. Continue updating to the next BIOS version released. 0036 then 0037/0039 and 0042

3. If you encounter with issues finishing an update, please perform a BIOS recovery to the version that failed and then continue updating.

4. If you continue having issues after updating to 0042, perform a recovery to that version.

Some articles related: Desktop Boards — BIOS Update Instructions Desktop Boards — Instructions for Recovery BIOS Update

It is important to follow the procedure and not only performing a recovery to the latest version, this would be to make sure the BIOS updates are properly installed in your system.

Please perform the steps above and if the problem persists, do not hesitate to advise me.


Esteban C

Valued Contributor I

@EstebanC_Intel, I'm not the OP, but you have misunderstood the situation.

DH67 and DZ68 boards can have either Sandy Bridge or Ivy Bridge BIOS, but once the latter is installed the former can never be reinstalled. This is reflected in the release notes for these boards. 0028 is the newest Sandy Bridge BIOS and that is what the OP started with. Then he installed a Ivy Bridge BIOS and he was permanently screwed. The problem is and has always been, Intel does not warn of the consequences for moving to Ivy Bridge BIOS. And Intel washed its hands of the boards by not offering a service where customers could have the BIOS reverted back to Sandy Bridge for a reasonable charge. DZ68BC boards are especially problematic because of their OC capability which works well with Sandy Bridge CPUs and Sandy Bridge BIOS, but has severe problems with Sandy Bridge CPUs and Ivy Bridge BIOS.

Here is the exact text from Downloads: "Warning: BIOS version 0035 includes support for 3rd Generation Intel® Core™ processors. Due to structural changes in this BIOS version, once a board has been converted to this version or later, it will no longer be possible to downgrade the BIOS to version 0028 or earlier. Attempting a BIOS downgrade to a previous version may fail – the board BIOS will remain at its current version."

And to be blunt, a number of Intel support personnel have recommended that customers update their BIOS at the first sign of trouble when that course of action is the worst possible for DH67 and DZ68 boards. Not to mention that Intel's website offers this sage advice on Downloads: "Update the BIOS on your computer only if the newer BIOS version specifically solves a problem you have. We do not recommend BIOS updates for computers that do not need it."

If N.Scott.Pearson has a workaround to revert back to Sandy Bridge BIOS on DH67 and DZ68 boards, I would love to hear it. I tried to revert a DH67CL and failed.


Hello All:

Here you can find some instructions when updating the BIOS in your 6th generation Motherboard. Desktop Boards — Updating the BIOS to Support 3rd Generation Intel® Core™ Processors

sadpanda do not hesitate to advise me if you need further assistance with this situation.


Esteban C

Super User Retired Employee

Sorry, the only way to have the BIOS reverted back to Sandy Bridge would be in the factory.