Monitor Troubles to Looping Startup Tones

[Ledgem]

I have a strange case of hardware failure that I wanted to both share and receive thoughts on. I have an appointment scheduled with the Genius Bar in a few hours and so will hopefully be able to provide a conclusion to the case, but I'd appreciate the community's thoughts on it in order to make sure that nothing is overlooked (or that the Genius doesn't take me for a ride).

The system is a Mac Mini 2012, refurbished model that is still under Applecare. There were two old LCDs connected to it, one via DVI to HDMI adapter, the other via VGA to DisplayPort adapter. Keyboard and mouse connections were via USB.

We noted this morning that the display connected through HDMI wasn't displaying anything. The display connected through DisplayPort was working, but the resolution had reverted to 1024x768 (the monitor's native resolution is 1280x1024). The monitor model was still correctly identified by the system. The correct resolution could be selected, but it seemed strange that the system was choosing the incorrect resolution when it had no issues for months leading up to now.

I attempted to reboot the system, which led to the startup tone being repeated while nothing showed on either screen. To be specific, the tone would sound, there would be approximately one second of silence, and then the tone would sound again. I shut down the system, waited for 20-30 seconds, and then powered it on. It started up with no difficulty, but the HDMI monitor still wasn't working. I ran a system update (OS X 10.9.3 to 10.9.4) and restarted the system. I again received the tone loop. This time, however, I could not get past it.

According to a guide about startup tones from Apple, startup tones spaced five seconds apart is diagnostic of no RAM being detected. I timed the tones and found that they were closer to four seconds (counting from the start of one tone to the start of another). I have one upgraded stick of RAM in the Mini; I changed the RAM slot and then swapped back for the original RAM, but the startup tones were unchanged each time. I attempted a PRAM reset, which caused the startup tone to sound louder but otherwise did nothing. It seems like a case of hardware failure, and I can't think of anything more to do on my end to diagnose and/or fix it.

Interestingly, the monitor connected by HDMI also seems to have failed. I swapped the adapter for a DVI to DisplayPort adapter and attempted to connect it to my MacBook Pro. The system couldn't see it, and the monitor behaved strangely. Its power indicator showed that it had come out of sleep mode (it stopped flashing orange), but it didn't turn green to indicate that it had powered on. It remained blank, and pressing the power button had no effect.

It's a very strange coincidence that both a monitor and computer should experience operational problems at the same time, but as far as I know neither should be capable of inducing failure in the other. All of the components are wired into the same surge protector, along with a few other electronics that don't seem to have any issues.

Thoughts as to the issue are appreciated. I'll reply back with what Apple determines after they take a look at the system in a few hours.

 

[Ledgem]

Update

Summary: I suspect the VGA to DisplayPort cable is causing the problems. Full story below.

The Apple store visit didn't reveal anything outwardly wrong. The Genius booted into their diagnostic software without any issue, and the only issue identified was the hard drive, which is apparently posting failures for the SMART status. They wanted to replace the hard drive, but the symptoms don't match with hard drive failure. I asked if we could just try booting the computer normally, and the computer booted without any problems. We restarted it, and again, no problems. We swapped out their power cable for mine, and the computer still booted without any issues. They were pretty adamant that it was the hard drive, but had to admit that the hard drive issues they've seen didn't behave the way that I was describing. Since I upgraded the hard drive myself, I stated that I'd deal with it on my own and would return if the problem persisted.

Back at home, the system would not boot... again. This meant that there was a variable between home and the Apple store that was causing the problem. I changed surge protectors, changed the USB slots where the keyboard was plugged into, and unplugged the keyboard, but there was no change. Then it occurred to me to try booting without the monitor plugged in, and it booted without any issues. I plugged everything back in and even found that the monitor connected via DVI to HDMI adapter was working (I can't explain why it seemed to have problems with my MacBook Pro; I might have made a mistake on my part when testing it).

I rebooted a few times but couldn't replicate the boot problem again. The reason I suspect the cable has to do with other strange behavior. For example, I tried setting the monitor settings to "Best for display" again, which caused the monitor to display a black screen with an error message. I had to remote in through my MacBook Pro to manually adjust the resolution and frequency in order to restore image output. When the displays entered sleep mode due to idleness, the output on the display connected by the VGA to DisplayPort adapter had the entire image shifted to the right, and the screen displayed some information that it usually doesn't display (regarding the resolution and frequency).

It makes sense that a faulty adapter could cause such a problem. When DisplayPort became Thunderbolt, it granted greater access to the computer - a full PCI bus rather than simple graphical output. If the adapter were to malfunction in some form, it's possible that the computer would interpret it as something greater than a simple adapter. If the computer interpreted the adapter as a full device, anything could happen from there. This adapter is also suspect: it is a "genuine Apple adapter" that I purchased on eBay a few years ago. I have a number of adapters, both Apple and third-party, and the build quality certainly matches Apple's; however, I don't know what conditions it has been put through. It seems strange that it would fail without being touched, moved, or exposed to anything, but nothing lasts forever.

For now, I've disconnected that monitor. It's possible that the Thunderbolt port itself is acting up, but given that the Apple store connected their monitor through that port, I suspect it's just the adapter. I'll update if any other problems come up to indicate that the problem is actually something else.

 

[Crusher79]

Thank you, it was good to read that I'm not the only one with this problem. Nobody believes you when you say the vga adaptor seems to cause the problem. Now I reboot with the monitor switched off, then it's no problem. And soon i'll be purchasing a new monitor, wich will solve this problem.

 

[justinTlME]

Very good read considering I have been having TONS of issues with my 2012 mini and dual monitors. Still can't figure it out.