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Upgraded my cable connection from TW cable box to Mitsubishi WD-C657 1080P-capable DLP with otherwise appearing good quality Monoprice 1.3a Category 2 (24awg) HDMI cables and having problems: 1) initially, channel change caused screen to go black for 2-3 seconds (lived with delay; assumed delay necessary for HDMI or cable box or ?); 2) clicking noise from speakers using HDMI cable. So changed to second HDMI cable and clicking noise gone, but then: 3) screen eventually just stayed black. Never had these problems with cheap YPbPr cables. Changed to cheap composite and no problems. Is this an HDMI problem, TW problem, synergy problem, Mitsu problem? Any thoughts. Thinking to buy YPbPr cables tomorrow. Thanks.
Follow Ups:
Rebooting the cable box resulted in eliminating the black screen all the time, but still results in the black screen delay when switching channels.
David - Unfortunately, my Sony AV receiver is just a little too old because it has digital outs but no HDMI. Maybe we'll see if TW has yet another box to use (ugh - we must have changed boxes 5-6 times now in the last 2 years).
Mnilan - Never had a delay when using component cables - only happened when using an HDMI cable. Why is that?
PS - If the signal going into the cable box is digital, where does the conversion (DAC) take place? In the TW box or in the TV? Is either one better than the other?
Webnick:
As I understand it, TW has a new technical setup for dealing with many HD channels and limited bandwidth. Rather than send all HD channels to every cable box, they only send those that are being watched. So when you change channels, your set top box sends a signal to TW telling them which HD channel to send your TV. If someone on your block is also watching that channel, then it will come in on your Tv immediately. Otherwise, it takes 30 seconds or so for the signal to get changed at the TW end and get back to your TV. In my area, this technology was implemented in January but in your area, it could have been more recent. At any rate, some additional delay is "normal" now.
That suggests that its a cable box/tv problem. Almost no delay when the cable box sends an (analog) signal via its own DA converter to the tv. But interminable delay when the cable box sends a digital signal to the tv via HDMI! Could my Mitsu DLP be the culprit? I know its been set up correctly for HDMI and the HDMI cables are the recommended type, so . . .?
Webnick:
Yes, your delay could be a result of HDMI handshaking issues between the set top box and the display which is why you aren't seeing it when you use component. It could also be the HDMI cable itself - they get bent, stepped on, etc. I would check out another HDMI cable (buy or borrow) and switch set top boxes with TW before I would conclude that it's your DLP... Good luck!
"PS - If the signal going into the cable box is digital, where does the conversion (DAC) take place? In the TW box or in the TV? Is either one better than the other?"
That's easy to answer.
If the cable box is receiving a digital signal and you're using component output for video and/or analog output for audio, the video and/or the audio are being converted to analog in the cable box. It's the only place the conversion could be taking place if it has a digital input and analog output.
If you get a digital output from the cable box and feed it to the TV, then the TV will convert the digital audio but digital TV displays have no need to convert digital video inputs because that's what they use. Depending on the display and its tuner capabilities, it may convert analog video inputs, ie off air analog TV broadcast signals, to digital for display.
Which is better? Whichever one does the job better. That will depend on the quality of the conversion hardware/software in each.
In general I think you're better off feeding a digital video signal to a digital display. Why convert the video signal to analog only to have the display convert it back to digital so it can display the picture? There's 2 unnecessary conversions there if you can simply leave the signal in digital format all the way. Audio has to be converted somewhere so wherever the job is done best is best.
David Aiken
Webnick:
What you are describing is the new Time Warner way to deal with bandwidth problems. When you tune a channel, there is a signal sent from the set-top-box to TW which tells them that you've tuned in that channel, then they send that signal back. They are no longer sending ALL HD channels ALL the time. So, the delay is what is needed for the signal to go to TW and back to you and this is "normal." The black screen is your cable wiring telling you that TW needs to come and replace the cable from the telephone pole to your set-top-box. Good luck. I had to threaten to write to the NY State Public Service Commission or switch to Dish to get TW out to my house...
It could be an HDMI handshake problem between your cable box and your display. The simple way around that is to change either the cable box or the display and see what happens, ie borrow a different cable box (even just a different model from the same manufacturer) or a different display and hook them up and see what happens. If that gets rid of the problem then it's almost certainly a handshake problem.
The other solution may be simply to route the HDMI connection through an AV receiver. I had a problem with the HDMI connection between my previous settop box and my TV which went away when I connected via an AV receiver instead of direct so that the TV was handshaking with the receiver rather than the settop box. My handshake problem between the settop box and TV only occurred for that settop box with my TV, not with a different model TV from the same manufacturer and also not with a different settop box from that same manufacturer and my TV.
In my system I prefer HDMI over component but it's a very, very small difference that I wouldn't worry about either way.
David Aiken
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