BV Avant 32 DVD

[Sergi0]

Hi,

I get my hands on a BV Avant 32 DVD.  Type is 8448 and sofware is version 10.4.

I cleaned it to remove dust and I try to use it. It is not plugged with a source but I thought I could be able to check the menu and try to play with it. When I select a source, screen light up (see pictures), but immeditely close with a “sound” from the back…

Picture of the screen : https://ibb.co/whHTGbq

Does it mean the TV is dead ?

Regards,

S.

[Die_Bogener]

Dead?

No!

But close to it… not far away. Maybe 10 minutes? And bang!

The white lines are the runback of the cathode beam… and they should never be visible in standard mode…

Do not switch it on. It needs urgent repair of caps… power supply and deflection are not OK.

It still can be repaired, it just needs an old retired tv tecci and some parts…

Martin

[Sergi0]

Thanks a lot Martin ! That is helpfull. If I understand correctly, it can explode if I power it again ?

Do you have and idea of the root cause of this problem ? Is the moving of the TV a probable one ?

S.

[matador]

Die_Bogener wrote:

it just needs an old retired tv tecci and some parts…

Like everyone of us…

[Sergi0]

By any luck, do anyone know someone in Paris (France) area able to repair TV CRT ? I search a little bit with Google but no luck so far. CRT technicians are probably all retired… ;).

S.

[Die_Bogener]

Sergi0 wrote:

Thanks a lot Martin ! That is helpfull. If I understand correctly, it can explode if I power it again ?

Do you have and idea of the root cause of this problem ? Is the moving of the TV a probable one ?

S.

Transport?

No big TV or heavy electronics likes a transport. But if you take care not to smash it on the truck… no problem.

But this picture is typical for a bad power supply…

Switch it on? NO! First the caps die, then the transistors and chips… A cap can easy be replaced, a dead chip is a expensive desaster.

TV Tecci? It’s possible to learn it 😉

[Sergi0]

I am always open to learn. the gap is going to be big as I went directly into computer science and the electronics I learn wheren’t practical… But why not !

I took a couple of pictures on the back without the plastic case :

I did not notice an exploded capacitor or something that look deficient (aka burn or something), but my skills are low. Dust, I saw a lot of dust… 😉

Anything to look in particular ? I can also buy a working one and switch parts. This one is in very good cosmetic condition and I was looking for a grey one. The black one is more common to find around Paris.

S.

[Die_Bogener]

Cleaning is a good idea.

But dont use hard plastic tubes… a brush is better.

Much besser is compressed air… do it outside 😉

If there were exploded caps, then there would be no function at all, the TV would be dead.

The problem is: a almost dead cap looks quite like a new one, only if it leaks it can be identified or if it is blown up/deformed.

Caps dont like heat, so most of them die in hot areas and dirty areas… when they dont get cooling air/ventilation.

This hardware is already 20 years old, most units i repair are 30-50 years, not only B&O, also controller/relais in very old cars, fuel injection or controls . I usually take a board, clean it and replace all caps on this board. I dont measure them, testing takes time and is not 100% safe in circuit. I replace them all. Since i do not only one unit or whatever, i restore always 4-10 in series, using 1 test unit for testing the boards. I do only hardware i have for testing… or if it is very simple to find the defect. Starting with the Power supply is usually the best way to start…

Buying caps is not easy. There is not the best cap, it’s always a compromise. The most longliving caps are MKS WIMA, i replace almost every electrolyth cap up to 1uF with a WIMA or even with the new X5R or X7R SMD parts.

The bigger caps come from Panasonic, FC or FR series. They are not easy to get, right now they are very hard to buy… but 10.000h lifetime at 105 degrees are good material.

The problem is: you need a very huge sortiment of caps of every size and dimension to repair them in a usefull time. I think, i have around 200kg and around 25.000 caps in storage right now… just for my retirement.

[Author]

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