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Discussion Starter · #1 ·
Ok here is the problem...


I have had my x1 sitting on a table about 15 feet away from the screen. I ran my 50 foot VGA cable in the ceiling and have had it dangling down to the table. The power for the x1 has been plugged into a powerstrip and a outlet right by the table.. It has been setup that way for about 2 weeks and everything looked great..


So I finally made my ceiling mount. I ran 14-2 wire in the ceiling to the breaker box and added a 15amp breaker (along with a on/off switch in the equiptment closet to turn the power off to the projector.. The first 15 feet of the power run, runs along side the vga cable..


Last piece of info... I cut the plug off of the power cable of the x1 and hard wired it..


Problem: I get these weird scanning lines now.. They move slow and start and the bottom of the screen and move up... It takes and 25 seconds to go from top to bottom... You can see them mostly with a solid color picture (such as blue).


Any help would be awesome..


Thanks!!


David
 

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Quote:
Originally posted by david schmaus
power run, runs along side the vga cable..


Last piece of info... I cut the plug off of the power cable of the x1 and hard wired it..

David
Seems to me you now have a grounding problem--that's what it generally looks like.

Perhaps some of the real tech folks will weigh in.

Tom
 

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You have what is know as a hum bar. It is being caused by a slight difference in ground potential between your new X1 AC power and the AC power feeding the rest of your equipment. It is also never a good idea to run your video cable along side your AC power feed as this can also cause interference.


First try running an extension cord from the PJ down to where you used to have it plugged in and see if the problem goes away. Just let it hang in the air for your test. Then we can go from there.
 

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Quote:
I have had my x1 sitting on a table about 15 feet away from the screen. I ran my 50 foot VGA cable in the ceiling and have had it dangling down to the table. The power for the x1 has been plugged into a powerstrip and a outlet right by the table.. It has been setup that way for about 2 weeks and everything looked great..


yes i does sound like a grounding problem and does your direct connection have a ground or do you just see it while watching sat or cable or do you also get it while watching dvd .:)
 

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Could it be that the VGA cable is picking up noise from the AC cable it's running next to? Unless the cable is really well shielded this is not a good idea. One idea is to run a different VGA cable and a different AC cable (one at a time) and see which is the culprit.


JayW


Edit: UGH. I'm an idiot. I said what Adam Gutierrez said only he said it better. Sorry, should have read more carefully.
 

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Discussion Starter · #6 ·
Ok I will try that tonight... Also I left a loop of the romex in the equiptment room... Wire a outlet for the cable bo, receiver and dvd player then everything would be on the same breaker... Could that help?
 

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Discussion Starter · #7 ·
new teq joe: I see it with dvds also...


"Hopefully" I dont have to rerun the vga or power and its just a grounding problem... Obviously I would if I had to but they were a pain to run and I really dont have another path to get them separated..
 

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You should also think about pulling the 15 AMP and running a dedicated 20AMP line instead. I ran three seperate 20 amp outlets for my theatre so that I wouldn't not have interferance on anything. This way my projector, A/V Receiver and Sub all have there own power source. Might be overkill but that setup eliminates a seperate power stage unit. I still might get one for the cleanest power but nothing around my HT is affected by power drains in the house as if they were sharing power.
 

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I had the same issue, try lifting the ground from the X1 power supply (disconnect the ground wire if hard-wired, or use a 3 to 2 pin plug adaptor). If the bars go away (like mine did), its a ground loop, most likely the difference in ground potential between your A/C and your cable TV feed (even if its not hooked up directly to the proj., don't ask me why).
 

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Quote:
Originally posted by Opus33
I had the same issue, try lifting the ground from the X1 power supply (disconnect the ground wire if hard-wired, or use a 3 to 2 pin plug adapter). If the bars go away (like mine did), its a ground loop, most likely the difference in ground potential between your A/C and your cable TV feed (even if its not hooked up directly to the proj., don't ask me why).
The EARTH GROUND pin is there for a reason. Defeating that pin may result in damage to the equipment (most ESD protection is tied to earth ground) and/or may damage you (electrical shock). Never ever lift the earth ground pin unless you are qualified to do so. Even as an electrical engineer I never lift the ground unless I'm pretty damn sure I know what is going to happen.


A good solution is to create a harder earth ground connection. Also, do you have "cable" hooked up to your HTPC? If you do, try removing that connection before you go nuts. Cable television is often guilty of poor grounding. The scanning effect you see is often caused by a difference between the NTSC standard (59.9xxx HZ and AC frequency 60 Hz). This is why the bar moves so slow. Give it a try. If removing the "cable" connection off your HTPC fixes it, ground loop isolators are available.



-tReP
 

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Trepidation.


Please explain what you mean by a "harder earth ground connection."


Also, if you DO lift the ground on the PJ cord....then plug that cord into

the ground lifter, then plug the ground lifter into a multi outlet strip which then plugs into the outlet....


Did you still effectively lift the PJ ground, even tho the actual plug into the wall is a 3 prong?


Thx
 

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I described this same situation to my electrician this morning. I have dedicated circuits for the rack (2), sub(2), computer, and projector. They were supposed to all be on the same phase. I was testing the projector in the computer circuit when this popped up. So we think the computer circuit is not on the same phase as the rack and he will be fixing this next week. Good thing all new house stuff is still under warranty for a year!
 

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Quote:
Originally posted by Wonderment
Trepidation.


Please explain what you mean by a "harder earth ground connection."


Also, if you DO lift the ground on the PJ cord....then plug that cord into

the ground lifter, then plug the ground lifter into a multi outlet strip which then plugs into the outlet....


Did you still effectively lift the PJ ground, even tho the actual plug into the wall is a 3 prong?


Thx
A harder earth ground connection would be like what you see with the lightning protection on your water pipe into your house. This is typically an extreme by taking your earth ground signal from your circuit breaker box and tieing literally to GROUND!. This is an extreme case.


If you lift the ground in ANY case, the ground is lifted and thus not connected even if you put it into a three prong outlet. The third prong, like I said, is there for a reason. Manufactures DO NOT spend more money than they need to...and if they don't need the third prong, it won't be there!


999/1000 it is your cable connection which causes the humbar. To check it out, just disconnect your cable and it will probably go away. If this is the problem, you need a cable ground isolator. Cable is NOT a three wire signal but rather a balanced pair with the negative side being "grounded". However, since the "ground" for the cable receiver is not connected to earth ground, common mode noise can easily make its way into the system thus causing "noise". NTSC (analog cable) uses a 59.9xx something frequency. Typical refresh on a PJ is 60 Hz. 60Hz - 59.9xxx is about 1/10 a hertz which is why it takes about 10 seconds to cross your screen. Cable isolators, good ones, can be gotten from jensen transformers.


Anybody who recommends lifting the ground on consumer electronics is either stupid or ignorant. Doing something dangerous instead of spending a few $$$ to properly fix the problem is a sign that I don't want to be within a mile of you. Also, if somebody is hurt because you lifted the ground and they find out, your insurance WILL not cover it and your might as well reside yourself to a massive civil lawsuit.
 

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Quote:
So I finally made my ceiling mount. I ran 14-2 wire in the ceiling to the breaker box and added a 15amp breaker (along with a on/off switch in the equiptment closet to turn the power off to the projector.. The first 15 feet of the power run, runs along side the vga cable
If I'm reading this right you hard wired your X1 using only TWO wires back to your breaker box. WHY in the HECK would you wire a grounded piece of equipment to only two non-grounded wires? Especially considering it worked perfectly fine using the original 3 prong power cord.

If I'm reading that right you problem is BECAUSE its NOT grounded and/or running along side the vga cable. *confused*
 

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bob_vdi,

In the electrical world 14-2 is: a black 14 gauge wire, a white 14 gauge wire, and a 14 gauge bare copper ground wrapped in paper and all three conductors covered in a vinyl jacket. So his wiring run is properly grounded.
 
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