Lines on my TV screen

[imamartian]

I mean in the picture rolling down the screen.... anyone know what they are? and what causes them? and most importantly, how to remove them?

I have a Panasonic TH 42PX700B 42 Inch plasma TV, plugged in to a sky box (old, not sky+).

The lines are about half the height of the screen apart and run a varying speeds....

Thanks

 

[Sam Gangee]

More information required. Don't expect us to guess.

How old is the TV?
When did the problem begin?
Is the fault visible with only an aerial connection and all other equipment unplugged from the mains?
Is it Freeview or analogue?
If you remove the aerial connection and watch Sky via scart is the fault still visible?
If you remove the aerial connection and Sky connection and play a DVD is the fault still visible?

 

[Mickymoody]

I don't really understand from the description, you have lines on the screen, or a rolling picture or both?

On a CRT TV, lines on the screen would indicate flyback issues, that means there is a problem with the loptx, or its psu...but as your tv only has one of those....

A rolling picture would indicate crystal fail, so either the pict chip is broken, the psu is broken, the pict chip needs recalibrating. How/when did it fail?

I hate Plasma TV's as they are a gimme for TV manufacturers, not designed to work for over 5 years, but expensive to buy. Why people buy low quality goods is beyond me.

So 2/3 suggests the power supply is faulty. 1 suggest the main graphic chip. But without a proper description, it's a hard call. Do you have lines, or does it scroll?

 

[imamartian]

The TV is about 5 years old, flat screen plasma, HD ready etc .

The picture isn't rolling, but the lines moves down the screen.

Not Freeview, it's a sky box.

DVD looks fine.

TV is connected to Sky box via scart lead.

Will try just an aerial connected later as the kids ar watchjng a DVD

 

[ChrisFrost]

When I first read the OP I thought hum bars, but I would expect the speed to be fairly constant.

A little troubleshooting is in order I think.

Start by disconnecting all source equipment except for the aerial. Is the problem still there?

--- If yes, then disconnect the aerial. Is the problem still there. You'll have to use one of the AV inputs and set the TV to show blue screen if possible.

--- If no with the aerial only then add the Sky box. If the problem returns then it's an issue with the Sky box or something in the way it is connected.

 

[imamartian]

will do all of that... tomorrow... and get back. Thanks

 

[Sam Gangee]

So you appear to be stating that the old Sky Digibox is generating interference. That's not unusual and you have the choice of either replacing the failed capacitors (kits available for some models) or recycling it and buying a replacement (new or used).

Tell us the make and model number if you want a more specific answer.

 

[imamartian]

So you appear to be stating that the old Sky Digibox is generating interference. That's not unusual and you have the choice of either replacing the failed capacitors (kits available for some models) or recycling it and buying a replacement (new or used).

Tell us the make and model number if you want a more specific answer.

err didn't intend to.... the sky box seemed ok before the switchover happened here.

You asked for make and model... do you mean the tv or sky box? the tv make and model is listed above, and the sky box is a panasonic.

I plan to upgrade to SKy+ at some point - when i finally manage to work out their pricing structure for existing customers !!

 

[alansj]

When I first read the OP I thought hum bars, but I would expect the speed to be fairly constant.

A little troubleshooting is in order I think.

Start by disconnecting all source equipment except for the aerial. Is the problem still there?

--- If yes, then disconnect the aerial. Is the problem still there. You'll have to use one of the AV inputs and set the TV to show blue screen if possible.

--- If no with the aerial only then add the Sky box. If the problem returns then it's an issue with the Sky box or something in the way it is connected.

c
I agree with Chris, disconnect everything then try 1 thing at a time. first thing I thought when reading this was interference. Seen it loads of times, could just be a badly shielded cable

 

[Sam Gangee]

Certain Panasonic Sky Digiboxes are notorious for developing a fault like this. It's easy to test for it. Go into the Sky "Picture" menu and toggle the Scart output between "PAL" and "RGB". If the symptom disappears on one of the settings, your Digibox has a tuner fault. It can be repaired but cheaper to buy another 2nd hand box. Or simply leave it on the setting that removes the lines, for now.

Hope this is the answer!