Random Black Screens

[paulrbeers]

Originally Posted by Mac... nificent

Who said anything about broken cables? The subject is your "theory" that inferior cables are the same as expensive cables. Too bad for you that it's not provable with science, and your opinion doesn't count


Who are you trying to convince, everyone here or yourself, because from what you've said so far I don't believe your claim for a minute. Fortunately this isn't about you or me or anyone else, so back on topic


Both of your assumptions are not true. I guess in your world there is no binary code for color intensity. Apparently you missed 'school' when they were going over integer numbers and color quantization. Listen, I'm not here to convince you of anything. In the real world your ignorance on this topic will not effect anyone else but you, and I'm perfectly fine with that outcome


Amazing.

You claim you went to 'school' but you don't even know how digital works

If what you claim was true then a digital signal sent over a telephone line would not suffer the same distortion, attenuation and degradation as does a analog signal.

Your theory is easily proven false by simply using a long cheap cable in place or a quality 3 foot cable, and noting the differences in picture quality. The first thing a in-house tech will do when diagnosing picture quality issues is to try a shorter cable. Weird.

BTW, apple-win is right

Seriously stop. I DON'T have an electrical engineering degree (although did take ancouple ee courses in college before i decided on cs and mis) and even I can tell you that in a digital signal can not be degraded to the point where it is washed out. As pointed out earlier the bit is received or it isn't. If a signal/bit is lost it will either cause a slight flicker in the pixel of the list bit/signal or if enough bits/signal is lost it will cause a complete blackout. It will not cause an image to soften. This was what happened in the old analog days, but not in digital land. The image is always produced exactly how it was transmitted minus any data lost in translation in ONLY the effected pixels. Further this loss can ONLY happen in poorly constructed/out of spec cables. I always buy as cheap of cables for digital because in the end a 1 or 0 is the same whether I used cheap mono price or expensive monster cables.

[shanmugam]

Originally Posted by geraldfleck

Seems to have fixed BOTH the black screen AND snow screen. Haven't had one all afternoon.

what is a snow screen? grainy screen?

[apple-win]

Originally Posted by Woyzeck

Sorry, but I'm holding a communication engineer's degree, too, and your theories regarding digital communication are very bizarre.

HDMI uses sophisticated protocols (TMDS) to transmit a video image that are totally capable of detecting signal errors, including almost any forms of (analog) signal degradation that might be introduced by bad cables, electromagnetic fields etc.
There are several layers of error detection implemented (including parity data) that will be used by the display to detect (almost) any altered data.

The effects of an error rate that is higher than the protocols ability to compensate it are never ever washed out colors, but omitted pixels or lines.

However it's very unlikely that an off-the-shelf HDMI cable of reasonable length will render an HDMI signal unusable. Those gold-plated expensive HDMI cables are for freaks that have no idea about communication electronics.

I posted this info in my previous comment and started all these cable discussions. I don't have any degree.

******
Amphenol 28 AWG Ultra High Speed HDMI Cable [16.0 Gbps] + Gold Diecast HDMI Connectors + Nylon Net Jacket (1m / 3.3 ft)

http://www.cablesondemand.com/catego...nfoManage/.htm

Quality of cable does matter for digital signal error rate, no cable adaptor and straight-in is the best.

http://www.youtube.com/watch?v=XIw6lrghOt0
******


I think Amphenol is a good reputation multi-national company. It makes products for mobile devices, medical, military aerospace, and etc. Maybe Apple uses Amphenol products tooo.

http://www.amphenol.com

I don't agree that gold-plated expensive HDMI cables are for freaks that have no idea about communication electronics. I think $28.95 for a Amphenol HDMI cable is a good deal, it has a gold connector. Better deal than a white plastic Apple cable.

You are talking about HDMI uses sophisticated protocols (TMDS). I found some info in this link.

http://en.wikipedia.org/wiki/TMDS

It looks like 8b/10b encoding in TMDS is for EMI reduction and DC balancing, the link doesn't say it is for error detection. Even if it could detect errors, can TMDS correct errors? That's the key thing. Don't go cheap on cables, it's still cheaper than Apple computers.

By the way, 8b/10b encoding is old, Thunderbolt doesn't use it.

[motrek]

Originally Posted by apple-win

...
I don't agree that gold-plated expensive HDMI cables are for freaks that have no idea about communication electronics. I think $28.95 for a Amphenol HDMI cable is a good deal, it has a gold connector. Better deal than a white plastic Apple cable.
...
Even if it could detect errors, can TMDS correct errors? That's the key thing. Don't go cheap on cables, it's still cheaper than Apple computers.
...

Dude, we're just trying to save you some money. Your $29 cable isn't going to transfer a digital signal any more accurately than the same length of cable from Monoprice for $3.

As everybody with a relevant degree has pointed out, it's literally impossible for a bad HDMI signal to give you washed out colors, or a blurry picture, or any other thing you had to worry about with analog signals.

If there's an error, it will make one pixel go bad (out of what, 2 million?) for 1/60th of a second. That is well below the limits of human perception.

Basically, if you are seeing an image from your HDMI cable and it looks right, then it is.

If you want to be fanatical about signal integrity, it makes MUCH more sense for you to pop open your Mini and replace the internal SATA cable to the hard drive with something gold plated and nylon wrapped. It's much more important that the data you write to and from your hard drive not have any errors, and that data is transferred much faster than the data to your monitor. But I guess that seems a little silly, doesn't it?

[apple-win]

Originally Posted by motrek

Dude, we're just trying to save you some money. Your $29 cable isn't going to transfer a digital signal any more accurately than
the same length of cable from Monoprice for $3.

....

If you want to be fanatical about signal integrity, it makes MUCH more sense for you to pop open your Mini and replace the internal SATA cable to the hard drive with something gold plated and nylon wrapped. It's much more important that the data you write to and from your hard drive not have any errors, and that data is transferred much faster than the data to your monitor.

I appreciate your comment and opinions. I should not waste money.

Indeed I look at product specification before I buy. Amphenol gold cable has detail specification listed on the web page, not white plastic Apple cable, not Monster cable. I want to buy Mac Mini because it has a specification about fan noise, and it is low. Not even iMac has a fan noise spec.

I have a 720p Apple TV, 3 seconds white noise and audio hiccup everyday. Few months later I bought a 1080p Apple TV (I wasted money again.), white noise every hour but only in the morning. I exhanged another 1080p Apple TV at Apple store, same problem happened again and again. I used my iPad to film a white noise video for the worker at Apple stores. I got full refund even after 14 days. Then I bought a good quality 3-feet HDMI cable, it fixed my old 720p Apple TV white noise problem. You know even it happened 3 second a day, but it is audio hiccup and I was listening to iTune news radio, very annoying. I'm fine with white noise, but not audio hiccup over HDMI.

[motrek]

Originally Posted by apple-win

I appreciate your comment and opinions. I should not waste money.
...
I have a 720p Apple TV, 3 seconds white noise and audio hiccup everyday. Few months later I bought a 1080p Apple TV (I wasted money again.), white noise every hour but only in the morning. I exhanged another 1080p Apple TV at Apple store, same problem happened again and again. I used my iPad to film a white noise video for the worker at Apple stores. I got full refund even after 14 days. Then I bought a good quality 3-feet HDMI cable, it fixed my old 720p Apple TV white noise problem. You know even it happened 3 second a day, but it is audio hiccup and I was listening to iTune news radio, very annoying. I'm fine with white noise, but not audio hiccup over HDMI.

Sorry. Clearly you had a defective or broken cable. It happens. Anything can be defective or broken. I bet if you had bought a $3 HDMI cable to replace the broken one it would have worked fine too. Your repair strategy is sort of like replacing a broken Ford with a Ferrari. (Except a Ferrari that performs the same as a working Ford.) Anyway, I'm glad your system is working now.

[evanavevan]

Originally Posted by filman408

I have the same problem with my 2012 mac mini.

2.6 GHz, 16GB OWC Ram, Fusion Drive and 2 Thunderbolt display. No adapters involved.

Oddly enough, 1 display blacks out, and the other just has random artifacts and lines but never has blacked out. They are daisy chained together.

I did notice that the blackout happens when the processor is taxed more.

I have a similar setup and also getting them. Using 2.6 GHz i7 with 16 GB of G. Skill RAM from Newegg, Fusion Drive, and 2 TBD, no adaptors. Getting intermittent flickering to black. Seems like the firmware update supposedly fixed all the HDMI problems, but I'm still getting black screens. No snow. May have to return.

[apple-win]

Originally Posted by motrek

Sorry. Clearly you had a defective or broken cable. It happens. Anything can be defective or broken. I bet if you had bought a $3 HDMI cable to replace the broken one it would have worked fine too. Your repair strategy is sort of like replacing a broken Ford with a Ferrari. (Except a Ferrari that performs the same as a working Ford.) Anyway, I'm glad your system is working now.

I have tried many cheap HDMI cables at home for my Apple TV, I don't think they are all defective. That's why I have said luxury PC works well with luxury cable.

At this time, don't use good HDMI cable, we need control experiment to find out if the new firmware really fix Mac Mni HDMI problem.

[majkom]

This is epic fail, what the hell are they doing there in apple? seriously, if you still all have problems, just write directly to Tim Cook - let them work 24 hours/day to fix this... Last time I had problem with wifi on iMac under ML (common issue) - wrote to mr. Cook and he did care (next day - call from European HQ, tourbleshooting with technician from Cupertino - it did not solve the problem, but at least they cared). So my advice, send email, let them know there is a problem.

[motrek]

Originally Posted by majkom

This is epic fail, what the hell are they doing there in apple? seriously, if you still all have problems, just write directly to Tim Cook - let them work 24 hours/day to fix this... Last time I had problem with wifi on iMac under ML (common issue) - wrote to mr. Cook and he did care (next day - call from European HQ, tourbleshooting with technician from Cupertino - it did not solve the problem, but at least they cared). So my advice, send email, let them know there is a problem.

Run software update.

[majkom]

Originally Posted by motrek

Run software update.

LOL, and you just find thread with people that have updated and still have issue...

[evanavevan]

Apple just advised me put it in apple.com/feedback and that goes straight to their product engineers. Probably easier to send bug reports that we already know have no current fixes.

[Westyfield2]

Well a day later... do we reckon it's "fixed"?

[OldSchoolMacGuy]

Originally Posted by Westyfield2

Well a day later... do we reckon it's "fixed"?

Haven't had it happen at all since applying the firmware update. Before it was happening every couple hours at least. Seems resolved to me.

[Exodist]

Originally Posted by Woyzeck

Sorry, but I'm holding a communication engineer's degree, too, and your theories regarding digital communication are very bizarre.

HDMI uses sophisticated protocols (TMDS) to transmit a video image that are totally capable of detecting signal errors, including almost any forms of (analog) signal degradation that might be introduced by bad cables, electromagnetic fields etc.
There are several layers of error detection implemented (including parity data) that will be used by the display to detect (almost) any altered data.

The effects of an error rate that is higher than the protocols ability to compensate it are never ever washed out colors, but omitted pixels or lines.

However it's very unlikely that an off-the-shelf HDMI cable of reasonable length will render an HDMI signal unusable. Those gold-plated expensive HDMI cables are for freaks that have no idea about communication electronics.

LOL I pretty much agree with you. However I do tend to buy thicker cables with gold connectors, not that I expect better image quality. The thicker rubber just protects them from ravaging of my wife vacuum and the gold connectors sorta seem to be better against corrosion over time. Id prefer if they just made the ends out of stainless steel though instead of cheap metal.

Half my tendencies for thick cables are past reminisce of habbits from days of ega/vga days.. Old habits are bad to break..

Really really wished they would make more thin cables with nylon braid on the outside. Flexible and durable.

Now in regards to cables. I hate adapters and adapter cables. IMHO a CHEAP as dirt 1 piece cable is a much better option then two expensive adapter cables. I have had signal degradation so bad that pixels would twinkle and sparkle on the screen in high to low contrast spots. Getting a reasonable priced 1 piece cable always did fix it. This is also why I didnt use the adapter cable that came with my Mini. I just ordered a mDP to DVI cable for 14USD off new egg and was done with it. Never had a blank screen or snowing issue.

[Westyfield2]

Originally Posted by OldSchoolMacGuy

Haven't had it happen at all since applying the firmware update. Before it was happening every couple hours at least. Seems resolved to me.

Thanks. Looks like I'll be ordering myself one tomorrow then!

[OldSchoolMacGuy]

Would like to see more feedback from others. Plenty of people had this issue. Now no one has said anything since the firmware update was released yesterday. I would just assume that it's resolved things for people but it would be nice if people posted to say if they've seen any issues since applying the update.

[cutter74]

Seems resolved to me as well. Installed the update yesterday and haven't had a single hiccup since.

[k.alexander]

I only saw it a few times in the two weeks or so that I had the mini. Installed the update yesterday, did use the computer most of the evening last night. Have not seen the problem.

[davisac]

Originally Posted by OldSchoolMacGuy

Would like to see more feedback from others. Plenty of people had this issue. Now no one has said anything since the firmware update was released yesterday. I would just assume that it's resolved things for people but it would be nice if people posted to say if they've seen any issues since applying the update.

I was having about 3 a day and haven't had any since installing the update.

[jollino]

Only had one or so per week, so I can't really comment yet.

[great high wolf]

Bought a HDMI lead on the way home from work and hooked the TV up to the Mini as a second display. Didn't blackscreen whilst I was watching. Fingers crossed...

[fhall1]

As posted in a different thread....Set up my 2012 Mini Nov 26th using HDMI to DVI adapter....didn't notice any blackouts, flickers, whatever since then (about the magical 2 week point where some people started getting them). I do have the "crushed whites" issue but haven't tried any calibration (monitor is in PC mode though so it's not that). Installed the EFI update last night...no problems yet (but I didn't have any before either)....colors seem a little better, but still not great.

[mdgolom]

For what it's worth, I installed the update on Monday and didn't notice any more problems with the secondary monitor, but I'll admit I haven't used it much. I have my fingers crossed.

[Rob.G]

Another good report here. Installed the firmware evening before last. Yesterday when I got home from work, I noticed NO black-outs, snow or anything else. Normally, I would have one black-out within 5 min and snow within 30.

So far, so good. Now to see if this cures my TB display blackout crash.

Rob