Computer Causes TV Interference

[spammyyammy]

I am experiencing a weird problem with my computer. When I turn on my computer, it interferes with my TV downstairs and it won't receive any signal on a handful of channels (ITV, ITV2 and a couple other channels)dunwe. This issue has only happened when I moved my computer into a new computer case, with a new PSU and computer fans.

This problem is most noticeable when I am playing any computer game (I can't view any of the selected channels at all), which leads me to believe it's related to perhaps the GPU fan causing interference. Whilst playing, I have tried unplugging all my inputs which makes no difference at all, the tv still won't receive any signal.

I am using a TV aerial which is kept in the Loft and the TV is kept downstairs. I have tried using different plugs, cables, power wires and even a new monitor cable. My internet connection is by ethernet and we have no WIFI in the house.

One last thing, I hear a very quiet high pitch sound coming from my PSU, I'm guessing this sound is normal, but I am not 100% sure.

Thanks

Sam

[Matthew.Finger]

Hi there.

You have cable internet, yes?

Who set up the wiring in your house and who configured your modem? Is your TV and modem near eachother?

[colliebob]

There are so many possible variables in problems like this, it's difficult to know where to start. It may be the length of one of the computer or TV leads, for instance, and sometimes this kind of interference can be helped by winding the lead around a ferrite ring (google where you can get some). It could also be interference through the mains, and here again ferrite rings might be the answer. Your PSU does sound a bit dodgy and might need looking at anyway. Could be the fan by the sound of it.

[spammyyammy]

Hello,

Yes, all the internet in the house is wired to the modem, which connects to the telephone line. The TV and modem are about 5m away from each other, but I don't believe this is the problem as I have unplugged the modem whilst receiving the interference with no joy.

The PSU is brand new, so I'm hoping this is not an issue. Is there any way to test what could be causing the interference, eg the fan or PSU, or is it just a case of unplugging everything and plugging stuff back in one by one?

Thanks for the help.

[francis1234]

Hello
My suggestion is that you check the antenna of tv and see how you replace it with anew one and see if it works, if not call a technician to see the causes of the problems thanks

[colliebob]

Problem is, you replaced the psu and the fans at the same time, which makes identifying the offender that much more difficult. Suggest you put back the old psu first (assuming it still works) to see if that stops the noise, then the other fans one by one until you find out what's responsible. If everything else has stayed the same (mains and other leads, distances between the equipment), this should narrow it down to the real culprit. I'm no expert, these are just informed suggestions.

[spammyyammy]

Thanks for the reply. I have remembered though, that I did originally keep the old PSU in place. Then after a week of interference, I replaced the PSU thinking it could be that (an upgrade was needed anyhow).

What I have discovered this week is that, the intereference is most signficant when I play games, usually Battlefield 3 or Fifa and the interference can be temporarily fixed by removing the DVI cable from the graphics card and plugging it back it. I'm guessing I could need to get another, better quality (shielded etc) cable?

I've tried removing the fans etc and this doesnt seem to sotp the interference, however, I've not tried removing them whilst gaming, which could give another lead.

Thanks for the help

Sam

[BigPaw]

When you fitted the motherboard into the new case, did you use those little paper washers with the motherboard screws? When you use the computer, is the computer's case closed fully? All of the cables to your TV are seated properly? Either or both these scenarios (no paper washers, opened case) can cause Electro-Magnetic Interference. (EMI)

Because you are using a TV antenna, you are using a Freeview service? (Analogue TV has been switched off in the UK)

[spammyyammy]

Hello,

Yes, I am using Freeview service as Analog has been switched off for almost 2 years where I live.

All the cables to the TV are seated correctly and the setup has not changed at all over the last years.

The computer case is always shut when I use it. Hmm, I remember taking off the paper washers (I think they may have been some sort of rubber) off my board in the old case, but I don't remember adding them when I put it into the new case. I will check this when I am home.

Will this washer thing cause this issue? If so, are these easily buyable?

Thanks

Sam

(EDIT: I've just read that sometimes you should not use these washers with a motherboard. Could it be worth taking them out and trying it then?)

[BigPaw]

Well, it's more than good practice to always use the Mboard washers, the more protection for your computer the better, and all the more so when there are strange electrical anomalies.

You can also buy antenna signal boosters. You plug it into a mains socket, connect the cable from your antenna into the booster, and then an antenna cable from the booster to your TV.

If you can't identify the cause, which would be preferable, then for the time being it would be wise to attach ferrite chokes to video cables attached to your TV. Don't allow too many, in fact as few a possible, electrical cables to run with your antenna cable. Use surge protected electrical sockets with your TV and related equipment, and also with your computer and associated kit.

Do all the above things step by step, and if still no result, then it may be helpful to have the electrical wiring in your house checked. This process doesn't take long, using mostly the sockets. If you happen to celebrate Christmas then this test may be important to have done sooner than later, especially if you are like some of the people who live near me, you will likely be putting an increased load on your system in the coming months.

[spammyyammy]

I will check these motherboard washers when I am home.

I already have a antenna booster, as I live in the middle of nowhere ha.

I will also check the DVI cable from my graphics card and also try it with a VGA and HDMI cable to see if it's perhaps a dodgy DVI lead.

If I can't get these sorted, Ill look into getting some ferrite chokes and perhaps getting the wiring sorted.

Thanks for the advice.

[spammyyammy]

Just got home and I have seen that I'm not using the washers on the mother board.

Is this enough of an issue to warrant me getting/finding some more to try and fix the problem?

[BigPaw]

It really is your call, we are fishing for solutions to an odd problem that is related to something very unobvious.

I can explain the benefits of the washers, but make then a last resort if that helps. :)

[spammyyammy]

I think I'm going to have to go dig them out of the boxes now. The family wants to watch tv right now, but can't due to my PC.

I've found out though, the interference goes, when I touch the back of my case/unplug the cable and quickly reattach it.

Definitely has to be a grounding issue here somewhere.

I thought that the washers were literally just to stop you tightened the screws to tightly.

[spammyyammy]

I have now fixed this interference. A couple nights ago I resat my motherboard and used some homemade cardboard washers (probably not a great idea, but they're washers at the end of the day) and I also uninstalled my H40 water cooler for the original stock cooler.

I'm guessing that the H40 was causing the issue as I'm pretty sure my washers are good for nothing. However, I plan on reinstalling my water cooler this weekend and testing it for interference again.

Is this something that could have caused the interference or is it most like the washers?

Thanks for your help.

[BigPaw]

If any electronic or electrical device isn't grounded as it should be then you will experience anomalous effects. There was a definite cause and effect there, and if you recall that when you touched your PSU it alleviated the problem. So, when you were being a means for grounding, the problem stopped. Where was the current going when you were not grounding it with your finger?

I can only give this as advice, but I would be concerned if one electronic/electrical device was affecting another in my house. You might find it useful to have the wiring in your house checked, and it's not a complicated test. Please don't think I'm trying to frighten you. You may even be able to test it yourself?

[spammyyammy]

I have no idea when the current was going when it wasnt being touched. However, the issue is fixed now, but the only last thing I can do, is reinstall my water cooler to see if it was that causing the issue. If I install it again and it's fine then we know it was the lack of washers.

Thank you for the help solving this though.

[spammyyammy]

Quick update, I've pinned down the exact issue. It's all to do with my CPU usage. The higher my cpu usage the more interference it causes. E.g. 100% CPU usage = complete black screen, no signal received at all. CPU idling, e.g. 0-20% CPU usage, interference is medium, to nothing. I've checked, and it's not the CPU fan causing this. Think it might be time to buy a new motherboard and CPU

[djmndlss]

There is nothing wrong, and nothing needs to be replaced. My laptop does this with my antenna tv, the same few channels, and I've also noticed that sometimes my very own movement will affect the signal. Your computer's electronics are putting off an electromagnetic field, strong enough to disrupt the signal being received. I can wave my hand in certain places when it's just my own body interfering and the signal will come and go. Or I'll move to certain parts of the room. But when I turn on my laptop I absolutely cannot watch a few stations. I have an antenna in my window sill and the laptop on a desk nearby and I watch tv from the same desk area.

Your body is running on electric current. So is your computer. Perhaps the old case was a material that blocked the electromagnetic field, but I promise that's all it is.