LED Screens go Blank - Mac Studio M2 -> BMD HDMI/SDI Micro Converts

[Patrick Nims]

Hi - I've used Black Magic Design HDMI-SDI converter pairs for years with no problems. But in a new installation, my screens are randomly going blank.

The setup -
- two Mac Studio M2's with direct connected HDMI monitors.
- six Black Magic HDMI-SDI Micro converters pairs (three per computer).
-- Four new G3 converters and two original converters.
- six 70' 4k LED screens (Sony and Insignia, three per computer).
- brand new 3G/6G Belden 1694A/Canare BNC cable runs of 100' (three) and 200' (three).

The Symptoms -
Everything boots up fine and I see desktop images on all six screens. Within approx 10 minutes one of the screens will go blank without displaying a "lost connection" message. The image can be restored to the screen by unplugging/replugging the thunderbolt adapter at the computer. Other details -

- It is never the same screen(s) that goes blank or the same pattern.
- Multiple screens never go blank at the same time. One might blank after 5 minutes and then another after 3 more minutes.
- It happens both on the Sony and Insigina displays
- Screens from both computers have randomly gone blank.
- It happens on both the 100' or 200' cable runs
- happens on both the G3 and non-G3 converters
- Never more than 3 screens have gone blank at a time and never all of the screens from one computer.
- Screensaver and power saver settings are off on both computers
- Remote desktop into the macs show the blank screen desktops as active.
- The direct connected HDMI computer display never goes blank.
- When the thunderbolt/HDMI adapter is unplugged from the computer, the screen shows "lost connection", meaning that the screen is getting some sort of signal.
- When the thunderbolt/HDMI adapter is replugged into the computer, the desktop image comes back on the screen

Any ideas? Thanks!

 

[FMEng]

I would try reducing the number of remote screens driven by each computer, to see what happens. Does the Mac show CPU, GPU, memory, and drive loading?

 

[Patrick Nims]

Thanks, FMEng, great suggestion. I reduced the number of remote screens to two per computer but still had a screen go blank after 14 minutes. This is with the computers sitting on Mac desktops with no foreground programs running. CPU activity at 2% to 5%. I still don't know why the screens are going blank. Any additional ideas are appreciated. Thanks!

 

[Patrick Nims]

FYI - Blackmagic Support says Apple has changed their Resolution Options, which has broken compatibility with a lot of our devices. They recommend that instead of using a Micro Converter HDMI to SDI, to use a scaler, like their Mini Converter UpDownCross HD, that will stabilize/force the resolution and frame rate to what you set it to, and then send SDI out from that unit to the Micro SDI to HDMI at the other end.

https://www.blackmagicdesign.com/products/miniconverters/techspecs/W-CONM-28

Does that sound right to anybody? I've got some on order.

 

[TimMc]

FYI - Blackmagic Support says Apple has changed their Resolution Options, which has broken compatibility with a lot of our devices. They recommend that instead of using a Micro Converter HDMI to SDI, to use a scaler, like their Mini Converter UpDownCross HD, that will stabilize/force the resolution and frame rate to what you set it to, and then send SDI out from that unit to the Micro SDI to HDMI at the other end.

https://www.blackmagicdesign.com/products/miniconverters/techspecs/W-CONM-28

Does that sound right to anybody? I've got some on order.

Yes. Also remember that BMD works on magic, and should the "Grant Petty" run out, the solution to most failures is to purchase something else.

 

[ruinexplorer]

Sounds to me like a failure in maintaining the handshake. When you disconnect and reconnect, it forces a renewal of that handshake. The scan converter will likely make a difference.

 

[TimMc]

Yes. Also remember that BMD works on magic, and should the "Grant Petty" run out, the solution to most failures is to purchase something else.

A reply to myself, to not alter the original...

To be fair to BMD (and Grant), they've done what Peavey did for musical instrument amplification and small time PA - make something more affordable for a larger market. BMD's camera / switcher / shading / playout and control ecosystem is comprehensive (yeah!) but that can become a huge problem when any part of it fails, which will happen. The stuff is affordable and if you can get what you need in 24 hours, there might not be a compelling need to spend another decimal, left of the point. But if you're doing shows, streams, productions or events where failure is not an option and even a hot spare swap might be "forever" in Stage Manager Years, you won't find BMD in critical places.

If video were audio, the analogy I'd make is "this is like JBL... JRX, not MRX, PRX, SRX, VerTec or VTX". It's entry level, pro-sumer gear that is surprisingly flexible and full featured. But once you've experience better stuff (or had an embarrassing or expensive failure) you'll be looking up-stream for the next purchases.

 

[macsound]

A reply to myself, to not alter the original...

To be fair to BMD (and Grant), they've done what Peavey did for musical instrument amplification and small time PA - make something more affordable for a larger market. BMD's camera / switcher / shading / playout and control ecosystem is comprehensive (yeah!) but that can become a huge problem when any part of it fails, which will happen. The stuff is affordable and if you can get what you need in 24 hours, there might not be a compelling need to spend another decimal, left of the point. But if you're doing shows, streams, productions or events where failure is not an option and even a hot spare swap might be "forever" in Stage Manager Years, you won't find BMD in critical places.

If video were audio, the analogy I'd make is "this is like JBL... JRX, not MRX, PRX, SRX, VerTec or VTX". It's entry level, pro-sumer gear that is surprisingly flexible and full featured. But once you've experience better stuff (or had an embarrassing or expensive failure) you'll be looking up-stream for the next purchases.

While I agree that Blackmagic gear is absolutely affordable, I don't think it's prosumer or entry level in any sense.
Sure there are features of each device that may not align with the "industry standard" version, but in my experience, personally Blackmagic hardware is way more solid than most, AJA and Decimator gear that I've used.
This is based on experience with converters, switchers (not minis), and recorders. I haven't used the cameras to know if they're in line with an Alexa or Venice, so no comment there.

There absolutely is a "modern" tinge to Blackmagic that I don't like - the notion that products can ship at 98% complete and be fixed with software updates.

 

[Patrick Nims]

Update for all - The BMD Scalers did no better than the Micro Converters. The issue was in the brand-new, non-apple USB-C adapters I thought would be fine (Anker). Once I switched to Apple brand adapters, the displays have been rock solid.

 

[ruinexplorer]

Glad you are back up and running