Reception or TV problem??

[tjohn]

Ok bare with me on this.... I have comcast digital + HD service in the Philly area hooked up to a Toshiba 57H84. Been working great for months, the last few week I've been getting these flickering horizontal lines that span the whole length (horizontally) and vary in size vertically from less than an inch to possibly a few inches. These lines come and go quite often now and I though were only when watching HD programing. I was wrong, I have my cable split in a way that alows me to switch the TV back to the regular ant. and watch straight cable signal bypassing the digi cable box and the lines are still there. So I called comcast and they had me reset the STB and leave it on (power on) for 24 hrs, this did nothing. I have a service call scheduled for this saturday. The only thing I haven't tried yet is to watch a DVD, if I do and the lines are still there it's my TV right??

TJ

[tbenson81]

If the lines were still there with the straight cable antenna input as well as the digital box, then a reboot of the box wouldnt do any good because you receive the lines on the antenna input also. This rules out an input problem on your tv because that would be 2 separate inputs that are having this problem. If you see the lines with a DVD then it is definitely your tv. If you dont see the lines with your DVD, it is something on the end of your cable provider.

[tjohn]

Yes, the phone tech was just going through the motions. I just went along hoping. I might try the DVD at lunch because now I'm worried that it might be the TV :(

Thanks!

[tjohn]

Well I tried a DVD and no lines! This is a good thing :)

[kevinw]

Sounds like interference over the cable line. Might need a new line installed or some kind of filter...The word Ingress comes to mind..
http://www2.dslreports.com/faq/3315

[TheAntMan]

No lines during the DVD is a good thing. It sounds like the cable line problem. It's good they are coming over to take a look. Glad it's not your set!

[tjohn]

Glad it's not your set!

You and me both LOL!

Thanks

[tjohn]

K, here's an update for referrence :) Comcast tech came out this past weekend checked everthing out and determined that my cable is not grounded at all! He said usually that wouldn't do anything (other than possible destroying my all my tv's from a lightning strike WTF!) however the local electric co has been doing work in the arear and he could actually feel slight shocks when he touched the small wire end in the middle of the coax, these he said are what it making the lines on my tv. He also said they are not strong enough to do any damage to the tv or the STB. So they're coming back out this week to re-route the cable all the way to the other side of the house, ground it at my power meter and then find the shortest route back the to side where my cable comes in to my den. He said signal strength shouldn't be a problem since it's very strong but he would get me a signal booster if need be.

Sheww! TJ

[TheAntMan]

Good figuring out. Weak cable feeds are more common than we think. A Couple of years ago, first getting a cable moden and hi-speed internet, I got it home and set it up....only it did not work. I called the cable co. and the signal was not strong enough. Later that day......hi speed all the way!!

[tjohn]

Well here's some bad news :( The lines are still there!! Now what should I do???

[mjones73]

Did Comcast ground the cable at the same point your house wiring is grounded?

[tjohn]

I'm not sure where my house wiring is grounded at, but comcast grounded it right on my house (outside) power meter. They also installed another box right next to the power meter which have the cable going in and out of.

[Splicer]

One or two horizontal lines scroll from the bottom to the top (if that is what the lines do)?

[tjohn]

No not really. They don't scroll at all, they pop in and out at all parts of the screen and are only there for a second or so. But they do go completely across the screen horizontally. It made sence when the cable tech said small power surges. I don't know, I'm thinking of calling dish or something. I would still want my cable internet though.

[Ratman]

Maybe RF interference? Any businesses nearby with neon signs?
Electrical motors/genertors?

[tjohn]

No, but there is a huge cell phone tower about 100 yards away. But that has been there forever?? And this just started like a month or so ago. I'll have to ask my neighbors if they're getting anything.

[tjohn]

Watched a DVD last night and saw some the lines :( I even disconnected the main cable feed and I still saw them, but not nearly as frequent with it connected. Could it be something wrong with my power outlet, or has anyone had anything like this with a toshiba??

[Ratman]

Do you have any 'dimmers', baby monitors, fluorescent lights, fish tank pumps, etc...?

[tjohn]

Well the circuit that my tv is on is a messed up one. It has half my kitchen on it but nothing is on while the lines are happening. One major thing that has changed in the past 4 months is I had a propane gas fireplace insert installed into my existing fireplace which is only about 4-5 feet away from the tv, also the propane tank is right outside and also about 5' away.

[tjohn]

And BTW... thank you very much everyone trying to help me! It's very much appreciated :)

TJ

[Ratman]

Well... I don't think the gas line for the fireplace has any direct impact since no electric is involved (as far as I know).

what do you mean that the circuit is a "messed up one"?

If you think that may be suspect as a contributor to the problem, try running a heavy duty extention cord to a circuit that isolates your gear from the kitchen 'stuff'.

[tjohn]

There is a 3 spd fan on the gas insert but I hardly every have the fan on.

Half of my den and half of my kitchen is on that circuit, just seems strange the builder would wire it like that.

OK, I'll try that. Should I isolate just the tv or the whole deal (tv, stb, a/v receiver) ?

[Ratman]

I'd start with the 'whole deal' and work back. (process of elimination)

[tjohn]

Alright, I'll try it tonight. Comcast is coming back out tomorrow morning too.

[stuckinthemud]

This may be a long shot for you, but here's what I found this weekend at my house.

I had some flickering similar to what you described...but it was intermittent. When I got the flickers, they would last for an hour or so and then disappear for a couplecouple hours to a couple days. The flickering was pretty bad on Sunday. I had a couple new component wires and an optical wire I wanted to install so I drug the TV out of the stand and turned the STB and sound system around to re-wire it all. While I was back there doing wires I decided to split the cable to go to both the STB and the TV Coax input. The cable guy had put a straight through coax adapter in the line to add about three feet of coax so he could reach the STB. I replaced that straight through adapter with my new splitter adapter.

All the flickering went away and stayed away after this.

I deduced (unscientifically) that the straight through adapter must have been bad. I chuked it into the field as far as I could through it. My dog ran out and retrieved it (took about 20 minutes to find it) so I tossed it in the garbage this time.

One bad connector in the lines throws the whole thing out of whack.

Nate

[tjohn]

Thanks Nate, sounds like you could've been experiencing what I am. Where the flickers the length of the screen horizontally? Did it just start happening out of the blue? Can a perfectly good adapter go bad just like that? I'll have comcast check the splitter back there too tomorrow.

[Splicer]

The 'adapter' mentioned is commonly referred to as a 'barrel' connector. A F-81 I believe is the 'techie' term. Unless the barrel was used, chances are it is fine. In all likelyhood the fittings themselves just needed to be re-seated properly. Ensure that all connections are tight, but not overly tight. After finger tightening, use a 7/16" wrench to tighten 1 flat further and no more. A special torque wrench is made but yo cant really use it for anything else so I wouldn't bother if I were you.

The 'flat' I speak of is the flats the wrench fits over on the fitting itself. Just tighten the distance of 1 of those flats and no more. Before the connector gets put back on however, double check that the dielectric (the white foam around the center conductor) is flush with the lip inside the connector and that the center conductor (solid copper claded center wire) is at minimum flush with the top of the fitting itself. DO NOT allow that center conductor to be longer than 1/8" past the connector. If longer, trim using a pair of needle nose with the little wire cutters built in if you do not have wire cutters. No real chance of cutting it too short so do not be concerned with that portion.

In all my years in CATV I have never seen a splitter cause the picture to 'flicker'. A splitter is a passive piece of equipment that either passes the signal being fed it or not. But wierder things have happened I guess so you may as well have the cable dude check it out (which he probably will anyway).

Connect a test set and see if the flickering continues. It sounds like a TV problem.

[Razor8]

Could a power conditioner help? Razor

[tjohn]

Thanks splicer, I'll check all that too.

What is a power conditioner?

[stuckinthemud]

Yes...my 'flickers' were across the entire length of the screen.

Splicer...I was not trying to say that the 'barrel' connector was bad. My point was that any connection in the wire could be the source of problems. Rather than try to make that connection work, I discarded the connector and replaced it (since I was replacing it anyhow...even if it was not bad).

I can force a flicker on my screen by shorting together two compnent video connectors. I have a pigtail laying next to my screen that I use to hook up a video game (my connectors are on the back of the set and it is a PITA to turn the TV around to get to them in my setup). Any shorted or loose connector or one with a cold solder joint might need to be inspected at the very least.

Back in 1983 when I trained for electronics testing and calibration I was taught one of the most useful troubleshooting techniques ever. This procedure has never been bested. It's called the wiggle test. Take all your connectors and wiggle them one at a time to see if the problem can be reproduced. Seems too simple...but could lead to useful inofrmation.

Nate

[tjohn]

Could it be a power probem, like surges coming in from the poll outside? I wonder if I could call PECO on that??

[tjohn]

Back in 1983 when I trained for electronics testing and calibration I was taught one of the most useful troubleshooting techniques ever. This procedure has never been bested. It's called the wiggle test. Take all your connectors and wiggle them one at a time to see if the problem can be reproduced. Seems too simple...but could lead to useful inofrmation.

Nate

Guess I'll try that too thanks! I think I might have to print this thread out LOL

[tjohn]

Not looking good. Cable guy just left and we pretty much narrowed it down to the tv. He hooked up a tester tv and we watched the lines come and go on the mine but not on the tester :( At one point they where REALLY bad. Everything looks ok cable wise. Now I need to find out if my manuf warranty is still good, damn it!! thanks for all the help here guys!

[tjohn]

6 months old, still under warranty! Called a local authorized service shop today and they're coming out this thursday afternoon. I'll let you all know what happens.

[Splicer]

We hope for the best for you.

[tjohn]

Well here we go again. Service man was out today for about 2 hours. He saw the lines, checked this and that, all connections are good. Opened up the front and back, banged this banged that, all good. He disonnected the cable and we played a DVD, lines where there. Went into service mode and calibrated (it was way off!). Told him everything the cable guy said about possibly being electrical from outside. Service man said it's either the TV or an outside electrical problem. Uh... Duh! So he's going to call Toshiba tomorrow and wait for a response from them. In the mean time I think I'll call the local power co. and see if they can check ..... something??? Poll, transformer, whatever!!

Not a good update huh :(

[tjohn]

Did I mention, this sucks!

[tjohn]

*** UPDATE ***

Problem solved and repaired (under warranty) Turns out it was a bad red gun. I was arcing causing the lines and also would through it out of convergence big time. Repair guy took the chasis to the shop for 7 days. Just got it back and all is fine :)

Thanks again for all the comments in this thread.

TJ