Replacement for a dead BV7-40

[stotty1111]

Hello all

Looking for suggestions for a replacement for the above tv, it died over 20 months ago, a local repair outfit tried valiantly to revive it all to no avail.

Are there any suggestions as to a good replacement set? I need a screen size around 40″ with hdmi feeds and scart perhaps, I use a BC2 with the screen for DVD playback and a pc for ‘streaming’.

[pepps]

Hello,

I would keep an eye out for a nice used BV7-40 mk5. I love mine and would certainly get another one if this one packed in, such a gorgeous tv.

Julian

Location: Kent, UK

[stotty1111]

I live in Brittany, Finistere, nearest B & O vendor is in Rennes, about 150 miles away, followed by Nantes 170, locally ‘stuff’ is a bit like hens teeth, dealerships are also a bit’snooty’ probably because my french is not top line!

Hey ho life’s a bitch!!

[jvezina]

What was the problem with the TV exactly? Also which version of Beovision 7 it was?

Thanks,

Jean

 

[stotty1111]

It was a 7-40 Mk6, and had lost picture but the sound was ok!

[jvezina]

Was the problem caused by a backlight failure ?

If yes, it is possible to repair the panel by replacing the defective LEDs (or fluorescent tubes for older screens). There are Youtube videos explaining the procedure. One has to be very careful when dismantling the LCD panel assembly (a flat aluminum box) to not damage the liquid crystal layer and diffuser sheet but this can be done.

The standard repair procedure is to replace the complete LCD panel assembly but if the part is  no longer available a last chance repair at the component level can be attempted.

Good luck,

Jean

 

[stotty1111]

I don’t know, the repair place did work for 2 x B&O outlets, the technician worked thro’ lots of suggestions from B&O all to no avail!

[Tabloka]

Hi Jean,

my 7741 has also trouble with the backlight. Someday during televison the screen went black and never get back again. I sent the TV to my dealer for repairing but he couldn’t fix the problem. So I got the TV back unrepaired.

I read a lot of backlight problems and also watched a lot of youtubes about this topic. In your comment it sounds that you maybe fixed a problem with the backlight by yourself. Do you have any suggestions to dismantling/disassabling the TV in order to get to the LED stribes?

Meanwhile I checked most of the DC voltages of the PCBs compared to the service manual. So far I found only one DC voltage which should be 5V but it was only 3V (PCB03 P005 Pin2).

Thanks in advance Michael

[YannChris]

Hi Stotty,

I’m in Brittany too, near Lorient.

Having some vintage products which need repair, would you tell me where did you send your TV for service?

Please, excuse my intrusion in your thread.

Kind regards,

Yann.

Location: Brittany, France
My B&O Icons:

[stotty1111]

Hi Yann,

The ‘sort of’ B&O  dealership in Nantes use 111 Services. I say sort of because they deal in a wide range of ‘stuff’,  not just B&O!

There is a dedicated B&O outlet in Rennes although my experience was a little negative, the owner got a little short with me because he would not give me any details of 2nd user tv’s. They at that time, 2 years ago, also used 111 Services in Nantes or so I was lead to believe.

I cannot find the relevant telephone numbers, addresses etc as they are filed in an old laptop, if time permits tomorrow or wednesday i will try to find said info!

[YannChris]

Thanks Stotty,

I found the informations about 111 Services and will contact them.

Kind regards,

Yann.

Location: Brittany, France
My B&O Icons:

[jvezina]

Tabloka wrote:

“Hi Jean, my 7741 has also trouble with the backlight. Someday during televison the screen went black and never get back again. I sent the TV to my dealer for repairing but he couldn’t fix the problem. So I got the TV back unrepaired. I read a lot of backlight problems and also watched a lot of youtubes about this topic. In your comment it sounds that you maybe fixed a problem with the backlight by yourself. Do you have any suggestions to dismantling/disassabling the TV in order to get to the LED stribes? Meanwhile I checked most of the DC voltages of the PCBs compared to the service manual. So far I found only one DC voltage which should be 5V but it was only 3V (PCB03 P005 Pin2). Thanks in advance Michael”

Good morning Michael,

I am following this thread because  my own Beovision 7 Mark III (15 years old, now used in my bedroom) has now a backlight problem. The picture is displayed for about 30 minutes, then it starts flickering and goes black, If I just turn the TV off and on, the picture shows again for about 3 seconds and then disappears. I have to let it cool about 15 minutes. After that, I am good for another 30 minutes of viewing. I followed the “normal procedure”: I contacted my local dealer and they will schedule a visit by a technician. If the problem is caused by the backlight  and they cannot fix it, I will have to follow the procedure described in Youtube (or ask them to do it)

The service manual describes how to dismantle the TV and remove the LCD panel. But before, checking if the 24 volt supply to the inverter is present is the first step. The BV7 Mk III LCD panel uses fluorescent tubes (CCFL) for the backlight. In my own case, since he TV works for a short time, there is probably a component overheating. Using a component freezer spray to locate it would be the first step. Perhaps it is just a cold solder joint.

These TVs were expensive and top class when new and are in my opinion worth repairing.

Regards,

Jean

[stotty1111]

are the 2 x vent grills on the underside clear of debris, just a thought!!

[Tabloka]

jvezina wrote:

… But before, checking if the 24 volt supply to the inverter is present is the first step…

That is maybe a problem. Because the Mk6 has no CCFL but LEDs there is no inverter but a driver board. And I think when one or more LEDs are not working, the whole panel gets no power (24V) for safety reasons. I am not sure about that but I am quite sure.

As I wrote above: PCB03 P005 Pin2 should be 5V but is only 3V!

Regards Michael

[jvezina]

Tabloka wrote:

jvezina wrote:

… But before, checking if the 24 volt supply to the inverter is present is the first step…

That is maybe a problem. Because the Mk6 has no CCFL but LEDs there is no inverter but a driver board. And I think when one or more LEDs are not working, the whole panel gets no power (24V) for safety reasons. I am not sure about that but I am quite sure.

As I wrote above: PCB03 P005 Pin2 should be 5V but is only 3V!

Regards Michael

There are also Youtube videos explaining how to replace the defective LEDs. I think that 24V is specific to CCFL tubes, the supply voltage for LEDs may be different. Check the service manual for the Beovision 7-55 that has LEDs.

Regards,

Jean

[Tabloka]

… Check the service manual for the Beovision 7-55 that has LEDs.

Hello Jean,
I don’t know where to get the Service Manual for the 7-55. In Beoworld.org there is only a user manual available. Any proposals?

Michael

[jvezina]

Tabloka wrote:

… Check the service manual for the Beovision 7-55 that has LEDs.

Hello Jean,
I don’t know where to get the Service Manual for the 7-55. In Beoworld.org there is only a user manual available. Any proposals?

Michael

Sorry for the mistake, the service manual is for the BV 11-55 MK IV. I downloaded it and the power supply voltage for the backlight is still 24V, even if the backlight uses LEDs.

Regards,

Jean

[jvezina]

stotty1111 wrote:

are the 2 x vent grills on the underside clear of debris, just a thought!!

I cleaned the two fans with a vacuum cleaner, and unfortunately, the problem recurs. The TV doesn’t come very hot, however.

[Chris Tritschler]

Hello all, I’ve started to repair a Beovision 7-40 (later model with the 4 HDMI inputs). Backlight doesn’t work. I heard there is a surface fuse on the T-con board that’s worth checking but mine doesn’t seem to have that. The next step is to check the elements of the back light which I presume will be LEDs. Further up the thread there is mention of YouTube videos showing how to do this. Can’t find those. Does anyone have links ? Thanks, Chris.

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