Hi:

I have a 2004 Beovision 1 and it has been performing really well for the time I have had it. However, just this week or so I have noticed something which may be nothing but I am wondering if anyone else has experienced it and if it is symptomatic of a large problem:

Basically I use the TV for av sources and not for TV. I mainly use my Laserdisc player and Xbox 360. I have noticed that once a week roughly when starting a source it starts displaying it and then there is a sound like a static crack and then the picture disappears for about a second or less before restoring immediately and no other problems occurring until it happens again a few days or a week later. I am hoping that this is just a scart issue but I have heard that when these TVs go wrong the whole chassis needs changing - does this problem sound to yo like slippery slope time or is it something standard and not likely to worsten?

 Thanks

Graham
 

I have an MX4200 with a working chassis but no PIN code ... this could be used to repair your BV1 should it prove problematic.

Neil 

We get a similar problem when using an Xbox 360 with a Samsung LCD. The Picture does not dissapear but every now and then we get a high pich noise that last less than under a second.

Craig

Graham,

Based on your "Problem Statement" outlined I would say that the most likely cause of your problem is EHT (Extra High Voltage) arcing from the tube anode plug or cable from it to the LOPT (Line Output Transformer).

This arcing normally occurs due to a build up of dirt which forms a bridge for the high voltage. Because the arcing draws current normally to the chassis, the EHT drops below the voltage which allows a picture to be displayed. As soon as the arcing stops, the picture will be restored.

When you change your source signal, the tube cathode current also changes which is often a trigger for the arcing.

The solution is for you or a service engineer to clean out the TV with a Vacuum cleaner and clean the EHT cable.

Hi Keith:

Thanks for your reply, I am quite happy to do it myself and will uprate my membership to gold so that I can get the manual for disassembly of the unit. I would normaly just go at it with a screwdriver. However as this unit is quite new, it is my pride and joy and thus I do not want any "why is this screw spare?" scenarios when I put it all back together.

I gather that I just need to take standard precautions when doing this. Namely, turn the TV off for about a day so that all the caps etc discharge and then gently hoover it all out?

The EHT cable and plug is the cable that attaches directly to the tube - right? Sorry, it has been a long while since I have had  TV open.

How soon do I have to sort this out? If I don't will it damage the set or will it just be annoying?

Once again, thanks for all your help. Looks like I have saved myself yet another costly bill.

Thanks

Graham

Graham,

First, let me say that the picture tube of any CRT TV is like a big capactor when the TV is switched off, so allowing a long time for discharge is important.

The tube "anode" is a seperate connection on the glass back and the cable goes to plastic covered plug on the tube which only has to be cleaned NOT unplugged. The cable will route down to the transformer which needs to have the dust/dirt removed with a vacuum cleaner.

The arcing you are hearing is called "Chrona Discharge" in the electronics world and was very common in older TV's. The problem occurs because the high voltage creates static which draws all the dust and dirt towards it increasing the liklihood of the problem

Hi guys:

Thanks for all your help. Can you quantify how long I should have the set switched off for. I would rather be ultra careful rather than get even the slightest shock. Got one from a boiler once and that was not nice - direct current, as much as you hate it, you cannot let it go!

Graham,

Leaving it for 30 minutes should be fine, but if you are unsure just take a screwdriver with a wire connected to it and the other end of the wire connected to ground, Touch the metal end of the screwdriver to the eht cap, any power left will go to ground.