HDMI dropout

[TNTRower]

Hi folks!

I have to admit that I am at my wits end.

I am running HDMI cable from my Comcast DVR/Cable Box (Motorola DCH 3416) to my Samsung Plasma. The length of the cable is 2 meters. I have wall mounts in place that are the flexible female wall plugs.

I have short 18" patch HDMI cables from the Box to the wall, and from the wall to the TV. The TV has 90 deg adapters for low clearance against the wall.

I had to make some tight turns and go through several studs. The issue I have and this is no joke, when I open the refridgerator, the current dips just enough that it kills the picture going to the TV.

The Fridge is on the other side of the house and on a different circuit!

I got rid of the cables and spent a little bit more on some cables. Same thing. However, when I use the short cheap cord (6 foot) that came with the Blu-ray player it works fine no matter what.

Also, the Blu-ray player goes down to 720 instead of 1080 in the same setup. Using another cheapo cord (6 foot) it is fine as well.

I have Composite Video and regular Analog running alongside the HDMI as well as an electrical leg.

Any ideas or suggestions?

Thanks!

 

[TLS Guy]

Hi folks!

I have to admit that I am at my wits end.

I am running HDMI cable from my Comcast DVR/Cable Box (Motorola DCH 3416) to my Samsung Plasma. The length of the cable is 2 meters. I have wall mounts in place that are the flexible female wall plugs.

I have short 18" patch HDMI cables from the Box to the wall, and from the wall to the TV. The TV has 90 deg adapters for low clearance against the wall.

I had to make some tight turns and go through several studs. The issue I have and this is no joke, when I open the refridgerator, the current dips just enough that it kills the picture going to the TV.

The Fridge is on the other side of the house and on a different circuit!

I got rid of the cables and spent a little bit more on some cables. Same thing. However, when I use the short cheap cord (6 foot) that came with the Blu-ray player it works fine no matter what.

Also, the Blu-ray player goes down to 720 instead of 1080 in the same setup. Using another cheapo cord (6 foot) it is fine as well.

I have Composite Video and regular Analog running alongside the HDMI as well as an electrical leg.

Any ideas or suggestions?

Thanks!

I would bet you have too many connections and bends. HDMI is very touchy. It is not robust in any way, and highly intolerant of set up deviations. Actually it is a misbegotten system.

You need a direct connection from box to TV in my view, like you have found out.

You need a big pipe like this to carry the cables to the TV.

Then something like this behind the TV

There is just one HDMI connector from receiver to TV, one plug at the receiver and one at the TV 25 ft long.

It end up hidden like this.

 

[TNTRower]

Oy!

Well I guess that would make sense. I would have thought that HDMI being digital would have been easy to maintain in terms of signal. Either it is there or it isn't.

Ok then I guess back to the old design board.

 

[TLS Guy]

Oy!

Well I guess that would make sense. I would have thought that HDMI being digital would have been easy to maintain in terms of signal. Either it is there or it isn't.

Ok then I guess back to the old design board.

HDMI is not a simple digital link. It is a two way communication, that has to make repeated handshakes. If these do not occur the signal is dropped. HDMI is mainly a complex DRM system to the benefit of the studios, rather than the consumer.

The system is constructed around HDCP codes, which are developed and endlessly amended by Digital Content Protection LLC.

There are 20 or so cables inside and HDMI cable, and yet the digital bandwidth is enormous.

The cable is very fragile and easily damaged by handling such as putting through walls and tight turns.

The next issue is that because the frequency of digital signals is so high they are prone to reflections back up the cable, and this looses data. This problem is magnified by terminations, as this is where most occur.

So when working with digital cables the rule is to keep terminations to the minimum.

Even when you do everything right the HDCP codes can still defeat you.

 

[skizzerflake]

You might complain to Comcast. I have been through several cable boxes which did different but similarly weird things. Those Comcast/Motorola boxes usually go through several customers before you get tham and might be abused by the time you get it. It might have a weak signal, which is being stressed by your connections.