Video wall display keeps crashing

[JVRaines]

i have a 3x3 video wall with Samsung UE55D Smart Signage displays connected in a DisplayPort daisy chain. The first display is driven by a PC over HDMI connection. The problem is that this first display crashes at random times -- it goes dark, taking down the wall, and has to be hard-reset by removing and reapplying AC power. I have had two different units in this position and they both crash. So I'm thinking there is a problem with the signal from the PC or maybe the cable. It's a long HDMI cable with RedMere. Replacing it is my next move (it's a big deal to fish it), but should I be checking anything else?

[TreeTops]

Since RedMere uses electronics to boost the signal along with thinner copper wires in the HDMI cable, I would suspect that something is happening there.

[jagabo]

Temporarily connect a source to the first display with a short cable. Still a problem?

[JVRaines]

Temporarily connect a source to the first display with a short cable. Still a problem?

In fact, the same wall ran for several months with a WDTV media player and a much shorter HDMI cable. So the main changes are using an active cable and connecting to a PC. I'm wondering if there is some signal from the PC causing it to conk out. The display doesn't just go into standby; it becomes totally unresponsive and requires a power reset.

[Cornucopia]

Pro setups for videowalls usually use one of the types of HDBaseT (incl. DTP, XTP, DM) to do the long runs. But then, they don't usually daisy chain them, rather they use a matrix DA/Switcher and all the signals go out in parallel.

I manage a 5x5 videowall with 55" NECs, powered by Crestron controller & TVOne switcher/DA. Downside of course was cost, cha-ching$$$!
Even at that level, there is downtime, though that usually only amounts to ~3-4 days a year.

**Note: Heat buildup can still be a major issue. Check your ventillation with well-placed longterm temperature readers.

Scott

[JVRaines]

These displays have a built-in video wall function to slice the image that comes across the DisplayPort chain. It's lower resolution than I would like, but all the venue has the budget for.

The wall worked for 10 months in the prior configuration without mysterious shutdowns. And now it's just the top left unit. If it were a thermal issue, I'd expect to have trouble with the other top units.