AVS Forum

AVS Forum (http://www.avsforum.com/forum/)
-   Digital Projectors - Under $3,000 USD MSRP (http://www.avsforum.com/forum/68-digital-projectors-under-3-000-usd-msrp/)
-   -   Random Video Loss (http://www.avsforum.com/forum/68-digital-projectors-under-3-000-usd-msrp/1437088-random-video-loss.html)

gorilla33 11-02-2012 08:27 AM

All of my equipment is routed through a Denon 591 AVR. The video cable from the AVR to my projector is 25 feet long and goes underneath my floor and behind my back wall where it comes through the wall and into my PJ. Occasionally when I get up off the couch, or close my recliner i lose my video signal, which then comes back after a few seconds. However, sometimes i can jump up and down in the room cannot replicate what is happening. Anyone have any ideas on what would cause this?

Mr.G 11-02-2012 08:46 AM

Quote:
Originally Posted by gorilla33 View Post

All of my equipment is routed through a Denon 591 AVR. The video cable from the AVR to my projector is 25 feet long and goes underneath my floor and behind my back wall where it comes through the wall and into my PJ. Occasionally when I get up off the couch, or close my recliner i lose my video signal, which then comes back after a few seconds. However, sometimes i can jump up and down in the room cannot replicate what is happening. Anyone have any ideas on what would cause this?

Since you own the Optoma HD20 try switching your HDMI cable to the other HDMI input on the projector. Also make sure that the connector is firmly seated. If the problem persists then I would suspect the HDMI connector on the cable itself.

gorilla33 11-02-2012 08:53 AM

i suspect the problem in the connection at the PJ. It is making about a 90 bend in order to connect. I ordered an elbow that has not came in yet, thinking that it could fix the problem.

Mr.G 11-02-2012 02:01 PM

Quote:
Originally Posted by gorilla33 View Post

i suspect the problem in the connection at the PJ. It is making about a 90 bend in order to connect. I ordered an elbow that has not came in yet, thinking that it could fix the problem.

That's likely where the problems lies even though I have to confess I have a fairly sharp bend in the HDMI cable behind my projector as well. If it is a stress issue the elbow should help out.

gorilla33 11-04-2012 02:20 PM

I installed the elbow last night and still lost signal once. It also caused the 1080p picture from the blu ray to have degradation with white flickering. Could it be that my signal is just barely strong enough. I know a booster will help with the flickering but will it also help with it completely dropping the signal which I was originally concerned about?

Mr.G 11-06-2012 05:51 AM

It's possible that some of the HDMI cable connectors are damaged and it may or may not have anything to do with the new elbow.

Symptom 1 - No Picture: Shut everything down, and then restart the system with all the connections in place. Watch the screen. If you see a notification of resolution (this is a function of the sink, source or both and may not be available on all equipment) chances are the DDC line has communicated between source and sink. This is good! The problem is probably video related. If you are using an active product like a cable box or satellite box, try using a DVD player. Many times the player comes on with the brand’s logo showing. If the picture goes off when you think the program material should have started, it could be that the HDCP is not getting the proper key.

This can be a cable issue or a hardware compatibility issue. Remember that the HDCP keys are transferred using the DDC line on the cable. The most likely culprit is the cable. If this is a long cable run then you need to try to trouble shoot this.

First, try a shorter cable if possible, or try another cable brand. It might be that another brand has less capacitance in the DDC line. Another possibility is that the internal capacitance of either the source or sink is on the high side of the allowable capacitance limit. In that case, you can swap out the source and/or display to see if a different configuration solves the problem. If it works on a short cable then you should be able to get it to work on a long cable up to 50ft without a HDMI amplifier. However if you purchased a very cheap cable you will need to rethink your purchase. A HDMI amplifier may help you. You would install it as follows... Short cable – HDMI Amplifier – Long cable. This way you have the strongest signal possible for the long run.

Symptom 2 - Sparkles: Usually more noticeable on black areas, sparkles tell you that you have a video data transmission problem. In most cases this is cable related. It could be just that the cable is not performing very well due to its length or it is picking up electrical interference. Shortening will improve the integrity greatly. Did you run the HDMI cable near electrical wires? If so try to move them and see what happens. You could also try to add a cable EQ to the system. Remember that, in most cases, a cable EQ has to be located at the very end before it enters the sink.

Symptom 3 - Flashes, No Audio, Pink Screen: This is usually caused from a bad DDC line not communicating properly. It can be time consuming because you have to basically eliminate all the good things to find the bad. First, power up the system while all the HDMI cables are connected. Then, if you can, try the products with shorter cables.

Here you need to see if the system works at all. Hopefully you have tried all these products before they were installed If for some reason the system still fails to come on, start using different inputs. You may find that your cable box will work and your DVD may not or vice versa. This can happen because of stray capacitance on the DDC line. This stray capacitance may be inherent in the hardware itself. If you think that this is the problem, try getting a DDC line conditioner. We have seen these types of problems completely go away when conditioning is introduced.

Symptom 4 - Picture Comes On, Then Goes Off This is a common one. In most cases, it is one of two things. If one or more of the video TMDS channels has a high bit error rate or is not working at all, you’ll have this problem. Many times it may come back with tear lines through it. It all depends on the display and how it reacts to the lack of complete data.

The second case is the DDC line is just not quite making it and HDCP is not getting a new refresh key. Here, replace the cable or make it shorter. If all else fails, try conditioning or using an HDMI amplifier.

HDMI Cables and Connector: Another possible source of HDMI problems is the +5V power line used to power the display's DDC communication circuitry when it's turned off. If this power supply is weakened, communication problems can occur. Some HDMI switchers, splitters and LED-illuminating cables take their power from this line, which is asking for trouble.

HDMI Pin 19, the hot Plug Detect, is 50 per cent shorter than the others, so tends to be the first to disconnect if the HDMI plug is loose.

Bear in mind too that HDMI cables don't like being bent – signal timing is critical, so twists and turns can degrade performance, particularly over long distances. HDMI performance can also vary between different connections that are on the same device; often, due to quirks of circuit board design, one HDMI socket on a TV offers inferior performance to another.

Read more: http://www.hdtvsupply.com/hdmi-problems.html#ixzz2BRjjkhdj

gorilla33 11-06-2012 08:40 AM

Just ordered a HDMI Equalizer Extender Repeater from Monoprice. I do have sparkles as well as flashing.

Any change this fixes the complete momentary loss of signal as well?


All times are GMT -7. The time now is 05:12 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.