intel DQ35JO showing in booting with non-blinking underscore at upper left side with E7 at bottom right side
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You can try removing the memory modules one at a time to see if that changes anything or gets you past the blank screen. Another thing you can try is removing the CMOS battery for a few minutes and then reinstalling it and powering up. This should reset the BIOS in case there was a setting issue that was causing the problem. Try connecting the hard drive in different SATA port as well.
If this troubleshooting does not work try removing every component on your system and start adding one at a time to see which one is causing the problem.