I am experiencing a problem each time I start up my Beocenter 1 TV. The picture is distorted with wavy horizontal lines which traverse up and down the screen mainly at the sides of the screen and these distortions disappear once the set has warmed up after about 2 minutes. The distortion occurs on terrestrial and satellite reception and on DVD from the built in DVD player. The set has been to the nearest B&O repair shop at great expense and although they saw the problem at first hand at my home, they were unable to duplicate it in their workshop or solve it. An aerial engineer who saw it recently said it was a faulty component - maybe a dry capacitor or a dry joint. Has anyone else seen this problem and has anyone any ideas on a solution? Replacement of a circuit board, perhaps? Many thanks.

Welcome to Beoworld,

I am sorry to note that your first post on the forum is with a problem with your TV.

Based on your brief overview description it sounds like your problem relates to "Field flyback blanking" circuit.

• Are the horizontal lines white ?
• When you say wavy horizontal lines, do you actually mean lines at about 10 degrees ?

Hi Keith - Thanks for your prompt interest. It is actually the picture itself that is wavy - there are no superimpoosed lines. It is as if the picture is presenting itself in a series of sine waves but only at the sides of the screen. The centre of the screen is not really affected. The movement lasts 90 seconds and gradually the picture stabilises. I don't think the problem is related to TV signal, as the same effect can be seen when I start the set up in DVD mode. (You will recall that the Beocenter 1 has a built in DVD player.) I hope this describes the effect more clearly and would welcome your further advice. Many thanks.

OK, then this is either a power supply issue or a problem with the degaussing circuit and both are linked. If the degauss circuit were to stay activated after switch on for more than a few seconds then you would get this type of symptom. The degaussing is regulated by a special type of thermister which changes resistance as current flows through it. This is the first area I would look at because the degaussing are arranged around the side of the tube, so will not really effect the centre of the picture.

Assuming I have understood your "Problem Statement" correctly then this problem will have nothing to do with the DVD player or the signal.

Are you a technical person who could do some tests inside the TV ?

The service profile from B&O, on your TV is to change the chassis.  

Not really a technical person, alas! Can follow a manual, but limited experience with electrics and electronics. And except for a screwdriver and basic stuff, no equipment. Is there an easy way to check if this is a power supply problem? The fact that the problem exists at home, but could not be duplicated in the service firm's workshop, may be significant?

The fact that the workshop could not duplicate the problem is not significant in my view. In my experience its very common for a reported fault not to show up in the dealers workshop and there can be many reasons for this, but top of the list is temperature.

I am sorry, but there is no easy way to fault find the problem without getting inside and doing a few checks, so I think you will need to get it back to the dealer workshop. I suggest they start by disconnecting the degaussing coils first and test the in-line thermister.

Thanks Keith - I will try again with the workshop and pass on your suggestion as to the possible cause of the problem. Many thanks.