Dell Optiplex 980 start up cycle issue with error code 134

Hi guys, I have a similar issue with my Dell 980 Desktop as it is written down here:

http://en.community.dell.com/support-forums/desktop/f/3514/t/19506518.aspx

However I've tried everything including disconnect peripherals, data cables, cpu, ram ... just with another error code, but no success.

I'm really wondering why the start up process is cyclic all the time like it is in this video:

Well, does someone have an idea what to do?

Thank you in advance

Regards

Stan