I’ve got a 7,1 Mac Pro with the Radeon Pro 580x video card. I’ve noticed the screen flickers occasionally (turns on and off briefly), when connected with an hdmi cable (hdmi on monitor, and on the Mac Pro). I recently added an adapter(hdmi to usb-c) into the mix so that the hdmi cable is connected to the thunderbolt3 port, and the flicker, at least with my brief testing period seems to have gone away. Has anyone else experienced anything similar?
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MP 7,1 Screen Flickering
- Thread starter pento
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I have this problem with screen going black for 1 second or so then coming back on. Does it a few times then stops. sometimes i also get a pink screen for a couple of seconds. it seems to come in little batches. resetting nvram and smc didn't help.
The issue appeared after i updated catalina to 10.15.4 there were no issues prior to this. It is connected via hdmi.
The issue appeared after i updated catalina to 10.15.4 there were no issues prior to this. It is connected via hdmi.
I can't say for sure what the fix was, because I had re-installed the OS at the time as well. However, it seems like the issue disappeared as soon as I switched away from HDMI. As an FYI, I was using a Dell U3014 when the problem had first occurred.
I'm now using a LG 5k UltraFine, connected with a usb-c to usb-c cable and I've still not seen it reoccur.
I've got this same issue. Flickers with the screen going black for a second or two, only ever when it wakes from sleep though it seems.
I'm on a BenQ SW2700PT with HDMI to HDMI cable.
I'm on a BenQ SW2700PT with HDMI to HDMI cable.
I think I can shed some light on this. I'm pretty close to 100% convinced from my personal experience and research that the flicker is due to HDCP (High-bandwidth Digital Content Protection) handshake issues. You can research this yourself, but basically the endpoints of an HDMI connection at the start of the connection go through a series of steps to ensure the devices are "authorized" to transmit high definition content. This handshake also is done periodically to verify the connection hasn't been tampered with. It is the absolute bane of HDMI. Any number of things can cause the handshake process to fail (bad cables, buggy drivers, firmware issues, barely signal compliant devices, incompatible[?] HDCP versions, etc.).
The FIRST thing to check is the cable. Seriously, if you think you have a good-quality cable, just get another brand and try that anyway. Check what the cable rating is (as far as HDMI compliance) compared to the resolution you are trying to use. You can try switching to a lower resolution as a debugging aid to see if the problem goes away.
Other than that, it's all bad news. Like I said, certain devices may have buggy firmware or sketchy signal compliance built-in. Getting a different brand device may be the only solution. If it's a driver problem then hope the vendor puts out an update.
I'm pretty convinced at this point Apple's drivers have HDCP compliance issues or bugs in them that cause issues like this. I've got an older system (2008 Mac Pro) hooked up to the same KVMP switch and monitor as 2 newer Apple products (MacBook Pro and Mac Pro 2019). All are running the exact same resolution. The older system has ZERO problems with this screen blanking. The two newer Apple products pretty much ALWAYS have this problem when I switch back to them. I "fix" it by quickly switching away from the system via the KVMP and then switching back. 99% of the time the connection stabilizes. If it becomes unstable again at some point I do the same process to re-stabilize the video connection.
Lastly, there is one somewhat shady area where you can fix this, depending on the resolution you are attempting to use. You can try to get an HDCP stripper. They're pretty rare at this point, but if you can find one it will very likely solve the problem -- assuming again it isn't just the cable.
Just want to chime in, as I have the same problem it seems. For me it happens after login, or when I switch monitor input (it is an older model from EIZO) from my old machine to my new MP7,1. Not only I have those intermittent blackouts, but sometimes also something that looks like noise, similar to an old TV set when there is no signal (but colored in this case). As I can solve this situation by switching the monitor off and on again it is not that there is no signal from my W5700X.
Think thomast is right, I also think this is something coming from faulty negotiation between monitor and GPU. And yes, I also use a HDMI cable which should be fine but I might testing with another one. As I plan to buy a new monitor anyway, I will check if this problem persists. I hope it is just an issue with that specific older monitor model.
Think thomast is right, I also think this is something coming from faulty negotiation between monitor and GPU. And yes, I also use a HDMI cable which should be fine but I might testing with another one. As I plan to buy a new monitor anyway, I will check if this problem persists. I hope it is just an issue with that specific older monitor model.