Hardware question-white bars of noise on tv output

[luxpyre]

This is a little off topic of the forum, but my laptop has an s-video output that I use to watch whatever on my tv. I also hook the sound into my reciever to get some semblance of surround. The problem is, I get white horizontal bars flashing across the screen that are very annoying as well as a low humming coming through the sound system that seems to "keep beat" with the flashes of white bars on the screen. This only happens when my laptop is pluged in. When running off of batteries, the noise and bars go away. I've been looking around for answers, but haven't been able to find much. I found one site that seemed to imply that the cpu can create interference when plugged in. It doesn't seem like it did this when I first go my laptop, but I may be wrong. Does anyone have any idea what this is and if there is a way to fix it?

[Quality's Proof]

I do not have a laptop.

Can you disconnect the battery pack and the laptop would run while plugged in? If so, is simple (free) solution.

If no, is there a setting/switch where laptop can be plugged in and battery charger off/on? If so, then try at both settings. If no, then you could call a Radio Shack, etc. and explain problem to them and ask for what you need. If I remember correctly one method is a "shield", I forgot what it is called......... sometimes really all that was required was a well-placed piece of plastic which insulated and thereby kept a magnetic field from forming (prevention and all that) which before had caused undue interference.

Also, do you know what a case gound is (also called an eqpt grd)? If so try that.

[luxpyre]

I have disconnected the battery and run straight off AC and I get the same problem. I have also tried moving things around if it was some field causing the interference. I have no idea about the case ground.

[Quality's Proof]

A case ground is also called an equipment ground. This is a conductor (wire) run drom the metal chassis to a grounding device (the grounding path where circuit is disconnected, usually).

In layman's terms you need a wire to run from your metal case of your laptop to some type of a piece of metal which is grounded. Sometimes a bare metal waterpipe is okay to run the wire to, but since plastic water pipe is common such metal pipes are not dependable. In US we have on 120 (110 volt) circuits three openings in the receptacle in the wall or above the counter. The center hole (@ top or bottom) is the grounding path. If the receptacle has only 2 hole then it is not a grounding path and therefore not to be used as such usually.

An alligator type plug clip is usually attached to the chassis (metal part of equipment (laptop)) and the grounding male end is inserted into the grounding opening of the 120Volt receptacle as a temporary bench test grounding path.

I am not familiar with most countries' electrical systems unless you are in Thailand. Such an electrical grounding pathshould further ground your laptop and discharge any stray current. Does this help?

[rsquirell]

You are in a country using AC...the problem goes away when using battery (DC). The Alternating Current is when the problem shows up...which leads one to think the S-Vid connection is loose or ungrounded...and the problem probably lies in the video card. If your card has a TV out RCA port, see if the "beat" problem is still evident when a RCA Composite cable is used. You can also try a GOLD, SHIELDED S-Vid cable no longer than 3'...the problem could be in the S-Vid connection, if you have a lousy cable.

[Quality's Proof]

I parenthesized "shield" in the 1st post, 3rd paragraph, 4th line. In some countries Ac is 120 volts and in some is 250 volts. In AC, @ 250 volts or so, there is a "sweet spot" for some effects......also, some transformers providing residences, are sometimes pinned @ a higher value than 250 volts. 50hz.

The field effect of a 120 volt and 250 volt is much different as is the taste of copper which their shock can produce, reminiscent of "old-school" apprenticeship.

Many battery chargers in some laptops are like some power supplies in some computers,,,,,,,waiting for a replacement.

[rsquirell]

Well, sure...it could be any of that...but if it were, don't you think there might be other interference problems showing up elsewhere? Right now we are in troubleshoot mode. If there is a RCA TV-Out on the card, testing it is free. A gold, shielded cable runs around $20-25. Switching out any internal pieces parts of a notebook can be extremely expensive.

[luxpyre]

I don't have an RCA out on the laptop. The battery is external and sits off to the side, if that makes any difference. The wires I am using right now are quite long, maybe 15-20ft since my laptop is set up a little ways from the tv setup. I'm thinking this might be the case becuase of the buzzing in the sound. I don't get that through the speakers that I normally use with my laptop which are external and use different, shorter cords. I'm not at home right now, so I cant try grounding the case.

[rsquirell]

There's a lot of loss through wires...even with that wierd battery configuration, it can't be the problem...because everything clears up when on battery alone. Move the 'puter closer to the TV, use the short S-Vid cable (you might use a dry toothbrush and brush off the pins to ensure a good connection.) If reception improves...but still isn't perfect, buy the gold cable...it's worth the extra money.

[Quality's Proof]

For a laptop, 15' - 20' is kinda borderline....I wouldn't want to use more than 8', unless I had spec'd the laptop. The gold wouldn't make that much difference as it would only lessen the connectivity resistance by less than 3 %, closer to 1 %, I'm thinking. The short length cables is better solution. Card doesn't seem to be a problem as battery pushes it well.

"....taste of copper which their shock..."

"...dry toothbrush.."

Am I clairovoyant or what??

We did agree to have fun.

luxpyre, you'll have to read the OFF TOPIC "Test Your IQ..It's fun.

[rsquirell]

LOL...the shorter the wire the better...and NASA loves gold...we have a lot of it burning up as satelites reenter...there's gold in them thar skies.

[luxpyre]

Thanks alot folks, I will try to find a replacement for these long things I have now.

[rsquirell]

Let us know of your (hopefully) success.

[Quality's Proof]

No need to spend lots of money on the cables, though : get the cheap RCA or something similar....the connectors' snugness is the crucial point as their connectivity predicates everything afterwards......the shorter cables will rule out loss, also don't make loops with the long cables as such makes another transformer effect.......I am wondering if it is the shielding of the transformer of the AC/IN which is the problem......aw, that Hysterisis problem, and of course that resonance.........

[rsquirell]

I was helping walk a fellow through getting his DVC-150 to work when he mentioned he was having a frame dropping problem. Everybody in the forum had thrown their two-bits in to help him solve the problem weeks earlier, to no avail. He had just spent a couple of grand on a brand new P-4 rig with scads of RAM and still the problem persisted. I suggested he switch out his wires for gold. It worked. I was God. He cussed himself for the new PC purchase. The solution was only $20. I had a salesman with access to measuring equipment telling me how much faster data moved over the USB2 port than the firewire...but he said with the measuring equipment he discovered he was losing almost 25% of that speed through wire loss...and that he got 100% when he switched out to gold. Of course, he was a salesman...selling me gold wire. But then, again...I've never experienced frame dropping. Oh...and the guy I helped was a professional PC Tech...he kicked himself saying he knew about the wire-loss problem, but never thought about it...his experience also jogged his memory about his audiophile days when he used to coat his wires with a special lubricant to improve the HIFI output. Lubricants to improve connectivity can be found at Radio Shack.