I'm having similar issues with my build:
Gigabyte GA-Z87X-UD5H (F8 Bios)
Core i7-4770K (using the integrated Intel HD4600 graphics)
16GB RAM, 8GBx2 Corsair Vengeance LP (CML16GX3M2A1600C10)
I have a dual monitor setup with an ASUS VG248QE connected via Displayport (when working) or HDMI, and an old Sony LCD monitor connected via DVI. All of this is connected to the integrated HD4600 graphics on the motherboard. Which ports are you using to connect your monitor? Originally I had been using the HDMI output for the ASUS, but switched about a month or so ago to the Displayport. Everything ran fine under 10.9.1, but within a day of upgrading to 10.9.2 (just did it this week), I encountered a kernel panic which a reboot resolved, and now if the Displaport is used and working, if I sleep the computer and wake it, the Displayport claims it's receiving "NO SIGNAL". Rebooting doesn't fix it either. I have no signal from the start, in the bios, or when booting into either OSX or Windows 7. In Windows connecting or disconnecting results in an audible noise indicating detection of something, but no signal reaches the monitor.
The first time this happened, after powering down everything, physically pulling the power cords from both monitor and computer, disconnecting the cable from both ends, and reconnecting everything, it finally came back to life and worked...UNTIL the computer went into sleep mode. I haven't been able to get it working again, so I'm back to the HDMI port which works fine.
Some research suggests it could the Displayport cable. I bought mine off of Amazon (http://www.amazon.com/gp/product/B005H3Q5E0/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1). It's highly rated, but some people speak poorly of the quality. It's certainly pretty cheap in price, but I was hoping it was similar to HDMI cables, where there's no need to drop $30-$40 on one. Perhaps I'm wrong here.
I also came across a post where a user with the same monitor had similar issue that was only resolved (and temporarily I believe) by physically disconnecting everything for 15 minutes, and then reconnecting the cables. Strange, but similar to how I got mine working again the first time. When I get some time today I guess check to see if this works, but for now I'm going to try and get a replacement Displayport cable. I'm starting to think this might not be 10.9.2 related, but rather a coincidence with the timing of everything.
EDIT: Here's a link to my thread which contains a screenshot of the kernel panic and additional details of my issue: http://www.tonymacx86.com/mavericks...770k-hd4600-graphics-16gb-ram.html#post790442
