[66Stingray427]

I posted this message in the rear projection forum for starters however seeing as this problem has spilled over to all the televisions within the household (LCD Flat Panel, Direct View CRT, and Rear Projection dispalys) I figured I'd stick it here and see if anyone else had any input.


In the RPTV forum someone suggested having my power company come and check out the situation. I scheduled an appointment but unfortunately the window for such appointment spans more than a week. So if anyone else has any other suggestions, be they off the wall, a band aid apporach, etc... I could really use the insight as this problem is driving me up the wall Thanks.


For some reason I just started having this problem a week or so ago and it appears to be a problem all over my house and with every television (Rear Projection, LCD, and Direct View CRT). Every so often when watching television or DVDs the picture suddenly gets darker or lighter.


Nothing has changed in my setup since the start of this problem so I'm really at a loss as to what could be causing it. I've seen a couple others report similar problems and having problems with their cabling or chaining devices together (Google resulted in finding a user with a similar problem who had his DVD player running through his VCR ) However in my case I'm using high quality cabling with digital or component connections making up 99% of my setup.


On top of that I've also noticed something else extremely strange that's been going on for a few months now. For one reason or other I'm getting little white or black artifacts on a large number of DVDs.


For a while it seemed to only occur in DVDs that were a year or so old but most recently I've noticed this problem in titles such as The Manchurian Candidate (this was actually one of the worst cases when it came to artifacts) and Saw. However other new releases such as Alien vs. Predator, The Village, Catwoman, Ray, Shaun of the Dead etc... etc... look absolutely stunning without a single artifact ever surfacing.


I've tested with a Denon 1910 (DVI Connection), Samsung 841 (DVI Connection), and numerous lower quality units from Sony, Panasonic, etc... and I've found that any movies that have artifacts when played in a given player will have those same artifacts in the same exact locations in any other player regardless of quality or connection type.


Now when I've sought help before, for lack of a better guess, it's been suggested that it's the discs but that simply can't be the case. I mean I've had this problem with dozens of disc, all purchased brand new and from a number of different retailers.


I've spoken with a number of the manufacturers of the various components but I've gotten no where. I talked to a number of local home theater experts however I was told by a number of them that they had never heard of such a problem and had zero suggestions, thus I'd say "expert" really isn't an appropriate description


The problem with artifacts however is not limited to DVDs as I've noticed this problem when watching a number of movies, even some in High Definition, on television. Oddly enough though the problem never crops us when watching standard television shows.


I'm grateful for any and all suggestions. Thanks

 

[semigolfer]

Quote:

Originally posted by 66Stingray427 I posted this message in the rear projection forum for starters however seeing as this problem has spilled over to all the televisions within the household (LCD Flat Panel, Direct View CRT, and Rear Projection dispalys) I figured I'd stick it here and see if anyone else had any input. In the RPTV forum someone suggested having my power company come and check out the situation. I scheduled an appointment but unfortunately the window for such appointment spans more than a week. So if anyone else has any other suggestions, be they off the wall, a band aid apporach, etc... I could really use the insight as this problem is driving me up the wall Thanks.

Typically when a utility feeds your house they bring in three wires. Two of the wires are at a nominal 120V, the other is the ground. In your fuse or breaker box, there are typically two busses (a copper bar to which the breakers are connected to) and a grounding bar. Each bar is attached to one of the 120V feeds. If you have appliances that require 240 V they connect across these two busses. Most of the rest of the house is wired for 120V, and the breakers attach to either of the busses.


I've seen a lot of strange things happening if you lose a good connection to ground, and the ground wire is then termed a floating ground. Voltages around the house can fluctuate all over the map.


In the best case, if loading is fairly balanced between the two busses, it might vary by only several volts, thus half your house might be at 110V and the other half at 130V. I've seen extreme cases where the voltage on half the house is 80V and the rest at 160V. Once the ground is floating, the loading on the breaker box somewhat determines how much of a voltage difference you see. Something like a refrigerator or a sump pump turning on can cause momentary voltage fluctuation. This condition is pretty easy to determine if you attach a voltmeter on a suspected outlet. If you don't have a voltmeter - attach a lamp with an incandescent bulb to the same outlet as your TV. If that bulb is seeing fluctuating brightness levels, I would turn off all major appliances, and disconnect all electronics from your outlets. If the unbalance gets extreme you will lose a number of your appliances. If your utility is that slow you could always hire an electician to get faster response.


PS your symptoms to date are very mild, so I can't be assured this is your problem, but it would explain it happening to several TV's as opposed to just one. Extreme cases incandescent lights will pop like flashbulbs.

 

[66Stingray427]

I will check the voltage tonight and see if it yields any obvious signs. Thanks for the suggestion

 

[rmcgirr83]

Please be sure an post back as a friend of mine is experiencing the exact same thing. Seems the DVD will go darker for ~ 15 secs then brighter for ~ 8 then dark again. Definitely a cycle...and this is with nothing else plugged into the outlet.

 

[66Stingray427]

Didn't get a chance to test this evening but I'll post an update before tomorrow evening.

 

[SolidState]

Quote:

Originally posted by rmcgirr83 Please be sure an post back as a friend of mine is experiencing the exact same thing. Seems the DVD will go darker for ~ 15 secs then brighter for ~ 8 then dark again. Definitely a cycle...and this is with nothing else plugged into the outlet.

This sounds like copy-protection. Is it hooked up thru a VCR?

 

[rmcgirr83]

No it is not...direct composite connection from DVD player to TV.

 

[66Stingray427]

Checked the readings today and everything seemed normal. A couple outlets I checked came in at 115V but most, including the main ones in question, came in right at 120V.


Just for the sake of being thorough I checked all the outlets on my surge protectors and even the outlet(s) on my DVR and Receiver. All checked out perfectly.



Oddly enough though, with no changes whatsoever in the mean time, the problem with the brightness levels seems to have disappeared. Now I've only had a chance to quickly test a few pieces of media so I won't write that problem off as solved so I'm still just as confused as before.


On top of this the problem with the artifacts is still present.



Is there anything else I can try on my own?? Do I need to be testing these outlets at different times of the day to make sure the readings are stable??


Also I did notice that the outlets in question did spark a bit when I plugged something in. It was minor and didn't happen all the time but it could be noteworthy. So if that's a sign of something that I'm overlooking I could certainly use some insight on that particular issue.


Thanks.

 

[66Stingray427]

Readings have remained stable for the past 24 hours. So, providing this would rule out a problem with the ground, anyone have any suggestions as to what could be the culprit here??

 

[markrubin]

one possibility is a bad (intermittent) cable or ground causing a ground loop problem from, perhaps, a cable TV feed: something you would not be able to measure by checking voltages


if you see this happen again, unplug any cable TV feed at its source and see if that has an effect

 

[rmcgirr83]

Thanks Mark but already did that.


It's definetly weird. I have to take time to go over to his house with my volt meter one of these days.

 

[66Stingray427]

You mean it's possible that the cable feed could actually be causing a disturbance with the DVDs, etc..


I don't doubt you I just want to make sure I understood what you meant before I run around the house unplugging all the cable connections

 

[markrubin]

Quote:

Originally posted by 66Stingray427 You mean it's possible that the cable feed could actually be causing a disturbance with the DVDs, etc.. I don't doubt you I just want to make sure I understood what you meant before I run around the house unplugging all the cable connections

yes this is what I mean


but just disconnect the CABLE FEED where it enters the house to see if that is the source of the problem: no need to disconnect individual sets:


you want to isolate the cable feed which maybe at a different ground potential than your house ground