Hello! I have a Mac Mini (late 2012) 2.3 GHz Intel core i7 running up-to-date El Capitan, with two HP 2071d monitors. These monitors have DVI connections. One is connected with Mini DisplayPort to DVI Adapter, and the other with HDMI to DVI Adapter (that came with the Mac Mini). All has been well for a year until this week. Both monitors have: 1) intermittently started flickering garbled images 2) intermittently flickering to black or white noise 3) intermittently flickering to white noise 4) displaying screen message “Input Signal Out of Range. Change Settings to 1600x900 – 60Hz”. How bad this problem is will come and go, but is rather persisting now. After researching, I have tried booting into Safe Mode, however the problem persists. I read that putting the computer to sleep, and then waking up could resolve this… it worked a couple of times, but issue soon returned. I have tried resetting VRAM/PRAM and SMC multiple times. I have doubled checked all the connections. Under System Preferences > Displays (when image is stable long enough for me to see it) all seems to be OK. Under the Display tab “Default for display” is selected. Under Color tab there are three HP2071d listed (with one selected) in Display Profiles window. I have tied selecting one of other “HP2071d” listed without any noticeable change. I also reset both monitors to factory settings via the monitors’ on screen menu. I also came upon this Mac mini EFI Firmware Update 1.7 for flickering on Late 2012 Mac Minis but when I tried to run it I got “this software is not supported on your system”. Ugh. Turns out my Mac Mini is already updated to MM61.0106.B0A (2015-002) My System Information>Hardware>Graphic/Display info is: Intel HD Graphics 4000: Chipset Model: Intel HD Graphics 4000 Type: GPU Bus: Built-In VRAM (Dynamic, Max): 1536 MB Vendor: Intel (0x8086) Device ID: 0x0166 Revision ID: 0x0009 Displays: HP W2071d: Resolution: 1600 x 900 @ 60 Hz Pixel Depth: 32-Bit Color (ARGB8888) Display Serial Number: 6CM3171PFF Mirror: On Mirror Status: Hardware Mirror Online: Yes Rotation: Supported HP W2071d: Resolution: 1600 x 900 @ 60 Hz Pixel Depth: 32-Bit Color (ARGB8888) Display Serial Number: 6CM3170P31 Main Display: Yes Mirror: On Mirror Status: Master Mirror Online: Yes Rotation: Supported I am out of ideas of what else to check/try. Cheers for any assistance anyone can provide.