2nd monitor keeps blanking out.

[GavinBKK]

I bought a Samsung SyncMaster S23B550 to go with my existing Samsung E2020 on a newly purchased Mac Mini. The E2020 is connected to the Mini from the Thunderbolt port, using the Mini-DVI adapter and functions normally.

The S23B55 is connected to the Mini with a separately purchased HDMI cable.

Here in provincial Thailand, voltage can be variable. When I hear the aircon unit click (is this a voltage drop?) the S23 screen blanks out briefly. The E2020 is fine. At first, I thought this was an issue of drawing too much current from the socket, so I connected the S23 to the UPS. No change. Still blanks out when the aircon clicks. Got a sparks to come and fit additional plug sockets, wired direct from the fuse panel and powered the S23 direct from there. No change, the S23 still blanks out when the aircon clicks. Just to add some spice, the S23 will occasionally blank out without the aircon clicking!

Has anyone got any idea what is happening and why??

TIA

[DeltaMac]

Do you ever lose the S23, when the other E2020 is _not_ attached? That is, using only the S23?

[GavinBKK]

Good point. I hadn't tried that and should have done. Will do now and advise.

[GavinBKK]

Yes, just powered off the E2020 and disconnected it and the aircon clicked and the S23 blanked out as usual.

[DeltaMac]

Can you possibly swap the displays?
Or, connect a different display through the HDMI port adapter?
The S23 also has a VGA input, doesn't it? Do you have a way to connect to the VGA instead of HDMI?
I think you would need to discover if the display is the weak link, or the HDMI port (verify the HDMI cable?), or something about the mini is too sensitive to slight voltage drops.

How about the possibility of a UPS for the displays, at least, or maybe a full-on power conditioner?
My first thought with your symptoms, is the S23 is just less voltage-tolerant, and power conditioning might give it some protection...

[GavinBKK]

I did try having the S23 plugged into the UPS, but no change.

I will need a Mini-DVI/Thunderbolt to VGA adapter then? Or a Mini-DVI-HDMI adapter, in order to try the S23 through the MBA?

I now have the Mini AND the S23 plugged into the UPS and the blackouts still occur??

[DeltaMac]

Is there a power LED on the S23?
When the screen blanks out, does that LED change color, or flash/blink, too?

If you don't have alternate adapter, to change how the S23 is connected, how about trying a different HDMI cable?

[GavinBKK]

Yes, I will ask around, but, without buying another, I am not sure who would have one around here. Getting one from the Apple Online Store will take a few days, so I will update when it arrives.

Do HDMI cables vary in anyway? By that I mean in throughput, not build quality, although that is a valid factor.

[GavinBKK]

No, the red LED stays the same. Does this point to the signal from the Mini being affected then?

[DeltaMac]

"Do HDMI cables vary in any way?
Sure, there's older cables that don't support audio through HDMI completely: there's various HDMI specs that aren't always supported in every cable. If you try a different one, be sure it's a different brand. Some will say they "fully support HDMI 1.3" or something similar to that. Do a google search for "latest HDMI specs" or something like that, to check for latest/newest cables.

[GavinBKK]

I'll play it safe and get one from Apple, eh?

Twice the price of everyone ale though, but I expect that now.

I could possibly get one from the relatively local reseller tomorrow...

[trevor]

Actually, Apple's HDMI cable is significantly less expensive than, say, Belkin's. At the online Apple US Store, right now, Apple's HDMI cable is $19.00, Belkin's is $29.95.

Trevor

[agentx]

Just get a new cable from a local supplier and do not pay the Apple tax !

Indeed there are some differences between HDMI versions built into your devices but really most devices from 2006 support v1.3 HDMI and 2009 is 1.4 (support for 4k,2k etc) but overall it is the old electronics supplier con game too. "Yes Sir this £65 HDMI cable is much better than this £10 one" well 99.9% of the time this is BS !

[GavinBKK]

@trevor: OK, but still more than an alternative one here.

@agentx: That's what I bought first and that cable is now my main suspect. As well as being very heavy, I woke this morning to find the monitor video feed blinking on and off - not, I stress, the monitor itself. I disconnected the HDMI cable and the monitor is sitting there happily showing nothing, but obviously no video feed. The Apple reseller in Hat Yai (35Km away) has the Apple HDMI, so I will get one later today. Someone did say that life wasn't meant to be easy!

[GavinBKK]

Apple (but it is black???) HDMI cable installed and the monitor is totally stable so far. Aircon clicks and no blackouts.

Being Thailand, there is, unfortunately, no way I will get my money back for the dodgy HDMI cable that I bought initially.

Sorted anyway.