I just got a new Mac mini MC815 i5 2.3 Ghz a few monrhs ago, and I added 8 GB of RAM and a 750GB 7200 HD then did a fresh install of Lion 10.7.4 a few weeks ago. When I use the Mac mini on any normal 24" Acer PC LCD via HDMI to DVI adaptor or Thunderbolt/Display port to VGA adaptor the Mac mini boots normal. I see the Apple logo and and spinning wheel for about 35-40 seconds and then see the desktop like normal.
As long as I use the mini on a PC LCD panel, there is no problem. When I try to connect the mini to a 32" or 42" television via direct HDMI cable... the colors are all screwed up. I see the apple boot logo, but it is green instead of grey. I tried 2 different TVs and 2 different HDMI cables. Both TVs are 1080p capable and work fine with Windows 7 PCs over HDMI or VGA at 1920x1080@60 or lower. The TVs have 2 HDMI inputs and 2 VGA inputs, so I have to use the VGA adapter. (can't use DVI)
I used the Thunderbolt/Display port to VGA adaptor and the colors are fine. All resolutions work, but I nomrally use 1280x720@60 so I can see the icons better from across the living room. Anyhow everything works perfectly with VGA, except there is no startup screen or logo and it takes a long time to boot after the chime. The TVs are blank and say "No Signal". I timed it with my watch on several occasions and it takes between 90 seconds to 2.5 minutes to boot to the desktop, but the TV says no signal while it is waiting. After the desktop finally comes up, all is well.
I tried 1920x1080, 1280x720, 1366x768... still the same problem. Slow boot, no bootup screen or logo but after boot is finished, everything shows on the TV and fits in the frame (no underscan problems) and the color is normal. The computer is fast and responsive. If connect the mini to a normal 24 inch Acer LCD to VGA I see the logo and it boots in 35-40 seconds.
Any ideas here? Do you think the mini is displaying the startup screen at an unsupported resolution and that is why the TV is blank? After the boot sequence, it finds the proper refresh rate or size then finally shows up? Or do I have 2 bad TVs? Or 2 bad Thunderbolt/Display port to VGA adaptors?
When I hook my 2011 2.3 GHz Macbook Pro (same 8GB RAM and 750GB HD upgrade on it too) to the Thunderbold/Display port to VGA, I don't have this problem at all. When I turn on the Macbook Pro, the Macbook screen shows the grey logo and the TV shows a grey screen until it is fully booted. However, the Macbook Pro also cannot use the Thunderbolt/display port to HDMI adapters either, the colors are usually green.
Anyone else have this problem with their 2011 Mac minis? I want to solve this problem before I buy a second mini for the bedroom TV. When I use my Windows 7 PCs via HDMI or VGA, I have never experienced these problems.