Thanks Stotty,

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

Kind regards,

Yann.

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

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

... 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

link

… 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

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.

Good evening,

Sorry for the long delay The videos on Youtube are not B&O specific. First, determine if your TV has a CCFL (fluorescent) or LED backlight. For the Beovision 7, I think panels with LED backlight were introduced starting Mk 5. To be certain, find the Samsung panel model on the sticker on the panel itself and search it on the web.

Then find a video about replacing LED strips or CCFL tubes. If it is CCFL check first if it is an inverter transformer that failed. There are also videos explaining how to check them. In my own case, that was exactly the problem. My dealer kindly gave to me a donor set for parts and I was able to do the repair by replacing the defective transformer as replacement panels are no longer available.

Good luck,

Jean