unstable picture when connecting MacMini to display via HDMI

Question

unstable picture when connecting MacMini to display via HDMI

I connect, using HDMI ports and cable, a MacMini to a Philips TV display typ 37PFL9604H/12 (of native display resolution 1080) using format 1080p at refreshing rate 60Hz, in line with the display info & request.

Most of the time the picture is good, the audio too like...

From time to time, at an irregular rate, the picture get a type of "negative" look such as...

...however the audio is good, the picture goes on moving, hence one can follow the movie.

After some tens of seconds or some minutes (at irregular rate) the normal picture resumes. And this happens many times within a movie or TV session (at irregular rate).

Alternatively, to get again a normal picture, one can select on the TV another external output, and switch it back to the used HDMI input.

I changed TV HDMI port on the TV, changed the HDMI cable,... no improvement.

To me layman, it seems that a handshake on colour control is sometimes missed.

Do I have improper settings? Settings during the session are shown in the following 4 figures.

Is the HDMI interface from the MacMini (model mid 2011) getting old / weak or unreliable?

Is the TV HDMI interface faulty?

Can anybody give me good hints to fix this?

Thanks in advance.

Settings:

Mac mini

Posted on Jun 2, 2015 2:22 PM

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Answer 1

Best reply

lllaass

Level 10

210,411 points

Jun 2, 2015 3:00 PM in response to michelfromoegstgeest

Could be a hardware problem like GPU problem especially if yo have the 2.5 GHz i5 or the dual-care i7 Mini (Macmini5.2) since those have a dedicated GPu while the other 2101 Mini's (Macmini 5.1 and Macmini5.3) use the GPU integral to the CPU.

Do you have another HDMI monitor to test?

Hu can try running Apple Harware tst/Diagnostics

Using Apple Hardware Test

However, thaa testing is not that good for GPU problems

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Answer 2

Jun 3, 2015 2:27 PM in response to lllaass

Illaass,

Thanks for your reply.

First, attached the characteristics of my MacMini, in case it can help in shaping your reply...

Second, I made a test replacing the Philips TV set by a (smaller) Sony Bravia :

product identification KDL-23B40xx
display native resolution is 768
format used 1080i
the user manual requests 60Hz refreshment frequency

Settings are show in the following figures

Figure 2 scaled 1080i 60Hz

Figure 4 colour control

Figure 5 details of the current colour profile:

I have not made any change: I do not feel qualified

Figure 6 I have not used these: I do not feel qualified

With the above settings, the picture on the Sony Bravia TV set was always good: no locking, no colour change, no problem for hours.

Hence the HDMI interface seems to work well on the Sony and on the Mac-Mini. However on the Mac-Mini the setting during the test with the SONY were different than when using the Philips TV, and hence I believe that one cannot exclude an error of the Mac-Mini for another set of parameters… Do you agree with that statement?

Thanks in advance for your input,

Michel

Figures 2, 4, 5 and 6 follow respectively...

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Answer 3

lllaass

Level 10

210,411 points

Jun 3, 2015 2:39 PM in response to michelfromoegstgeest

Does the Phillip's TV work OK with HDMI input on another computer?

I am leaning towards a problem with the Phillips TV.

It does not seem to be a setting problem since it coinages with time..

I would install a temp/fan speed app like Macs Fan Control and monitor temps and fan speed and see if yo can get a correlation of when the problem starts with the Phillip's TV. The Phillips TV's resolution may drive the integrated GPU/CPU to a higher temp than the smaller Sony

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Answer 4

Jun 6, 2015 10:04 AM in response to michelfromoegstgeest

For what it's worth, I occasionally have the same problem with my new Mini.

It seems to go hand in hand, although rarely, with the failure of the display to

wake from sleep.

Mine is an older Sharp VGA model.

I've found that when the monitor does this, if I unplug it from the mini and

replug it, it clears the problem. Also, oddly enough, when it does this,

I've found that opening System Prefs/Accessibility panel and clicking the

Invert Colors button on and then off, it clears the problem. Go figure!?

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