tv card interference

Willbo · 22 Jun 2006 at 22:59

tv card interference + PSU recommendations

my rig is as below but i have on two occasions tried a tv card to make the most of my dual monitors.....but both times i have been unable to get a decent picture.....first card was a freeview compatible Hauppage one where i couldnt get a picture at all. the second was an analogue Hauppage one where i got a picture but not a brilliant one off an aerial which gets me a good picture on my standard tv.

but i have recently discovered because of my parents moaning, that whenever i turn my pc on.....they get interference on itv. diagonal lines appear lightly on the screen. any idea what inside of a pc would cause this and if theres any way to stop it? also any ideas on how to get a tv card working ok for my pc?

Baron_Samedi · 23 Jun 2006 at 11:56

If the aerial is common to your PC and the TV then you are outputting noise to the aerial co-ax.... strange....

If the devices are using separate aerials then your PC is emitting shed loads of noise from the hardware within - best guess electrically noisy PSU broadcasting EMI via a window panel in your PC maybe?

Willbo · 24 Jun 2006 at 18:19

yeah it is strange and i'm getting more fed up because of my parents moaning now about my pc being on!

i first started using an aerial that was being used by tv downstairs and another in my room, but then i bought a separate aerial to try....and again....no luck with that either. can get a picture but not a decent one, and no freeview channels picked up either........

i'm going to try to get another PSU, if i remember my old one never caused any feedback on the tv so i'm trying to sell mine on ebay and get another. any recommendations? this will sound really strange but any recommendations by people who either have a tv or a tv close to the pc??? i'm desperate to get no interference. i currently (well for the moment) have the Tagan 530W PSU

Willbo · 25 Jun 2006 at 23:50

could someone please help in reply

Baron_Samedi · 26 Jun 2006 at 09:45

Ok, so you have bought a new aerial - is it a portable type aerial or one you attach to the building?

If its a building aerial then remember that the fins should be aligned vertically to properly receive freeview rather than the normal horizontal alignment.

Now, if you have a portable aerial (loop or ears) then you might not improve the situation. You could try holding the aerial in the air and pointing it towards your local transmitter in different orientations as you scan the frequencies and see if that makes a difference.

If this does not improve things - take it back and beg your parents to allow you to install a proper aerial :-)

Now, strange lining on screen is usually caused by electrical noise being induced in the circuits of a TV between the tuner and the display (owing to the coils used in their manufacture.

I would make sure that all the internal components of your computer are grounded properly ie screws in hard drive sides tightly fastened and the guides of any cards tightly screwed down making sure that the guides are flush to the case lip.

And.... then check the routing of cables - make sure they are routed around the mainboard neatly.

Make sure any earth tags for your PSU are fastened to the chassis and again, make sure that you have metal to metal contact between your PSU and the enclosure chassis.

Willbo · 27 Jun 2006 at 00:53

i'm pretty positive now the interference we're getting on our tvs is nothing to do with the aerials now as i no longer have a pc card or tv installed near my pc.

just took apart my pc and put back together to double check everything, i've now put a screw in everything just to make sure. moved the ground cable from the psu to another part of the chasis.....and still interference on the tvs when my pcs booted up. what could possibly cause this? i'm still thinking either PSU or GFX

Hudzy · 27 Jun 2006 at 03:40

You could try jump starting the PSU on it's own. That would either confirm it the culprit here or exclude it. Which ever.

If I recall, you need to bend a paperclip and shove one end into the end of the ATX cable where the green wire is, and the other into either of the black wires on either side of that green one. Do that before plugging it into the mains power supply just to be safe. Then power up the PSU.

Willbo · 27 Jun 2006 at 08:17

i'm actually having 2nd thoughts now as to whether it is my psu.

basically the problem only started when i upgraded my pc by replacing my memory with 2 1gb geil memory sticks, radeon x1900xt, tv card (which i dont have installed anymore) and 2nd monitor (which i no longer own)

And as far as i can remember my pc has never interfered with the tv until this point.

when i uninstalled everything last night but the basics, mobo, cpu, mem, gfx and hdd......i still got the problem, the interference occurs after the asus boot screen has closed when first turning on the pc, and you get the box displaying all the hdd installed, just before the xp boot up screen.......for some reason i am thinking its the gfx???? could i be right.......

Baron_Samedi · 27 Jun 2006 at 08:34

The next thing I would try is to make sure that the connections between your graphics card output and the lead to the monitor are firm at each end.

Then, I would get one of those clamp ferrites and apply them to each end of the monitor lead.

I would also check the firmness of the earth connection in the mains plugs of the computer and the monitor.