B&O Beovision MX4000 defective - UK Vintage Radio Repair and Restoration Discussion Forum

nikosyr · 11th Jul 2017, 10:52 am

Any help needed with B&O Beovision MX4000.

TV starts, but picture is very narrow in the center of screen. Channel changes and if i try to get to service menu shorting P700 i can see something happening on the screen.

No cold joints in the power supply or in the card thats on top of tube...

Heres picture how it acts. Someone specialist pls tell me the right direction. Next thing im gonna do is ESR meteri g all caps..

https://drive.google.com/folderview?...3VuOGttb2g4Sm8

Thanks for you help. Discussion free.

Maarten · 11th Jul 2017, 11:42 am

Problem sround the east/west or horizontal deflection. I think this is on the main chassis board in ths model. First check for loose solder joints there.

ukcol · 11th Jul 2017, 11:50 am

Check for dry joints on the back of the small PCB mounted on the scan coils (arrowed).

Common fault.

nikosyr · 11th Jul 2017, 12:10 pm

Thanks ukcol! It's alive!

https://drive.google.com/file/d/0B49...w?usp=drivesdk

https://drive.google.com/file/d/0B49...w?usp=drivesdk

Here's game picture

https://drive.google.com/file/d/0B49...w?usp=drivesdk

ukcol · 11th Jul 2017, 11:22 pm

Hi (Niko?)

I'm glad you got your set going again. That fault was very common with that range of tubes and by no means confined to B&O sets. Very often that little board was quite badly burnt by arcing when the sets were left on with that fault.

Maarten · 12th Jul 2017, 3:50 am

Ah, I thought you already checked that ("on top of the tube", actually at the bottom here but on top in most models) but you probably meant the crt connection board.

11th Jul 2017, 10:52 am	#1
nikosyr Retired Dormant Member Join Date: Jul 2017 Location: Tampere, Finland Posts: 2	B&O Beovision MX4000 defective Any help needed with B&O Beovision MX4000. TV starts, but picture is very narrow in the center of screen. Channel changes and if i try to get to service menu shorting P700 i can see something happening on the screen. No cold joints in the power supply or in the card thats on top of tube... Heres picture how it acts. Someone specialist pls tell me the right direction. Next thing im gonna do is ESR meteri g all caps.. https://drive.google.com/folderview?...3VuOGttb2g4Sm8 Thanks for you help. Discussion free.

11th Jul 2017, 11:42 am	#2
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: B&O Beovision MX4000 defective Problem sround the east/west or horizontal deflection. I think this is on the main chassis board in ths model. First check for loose solder joints there.

11th Jul 2017, 11:50 am	#3
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: B&O Beovision MX4000 defective Check for dry joints on the back of the small PCB mounted on the scan coils (arrowed). Common fault. Attached Thumbnails

11th Jul 2017, 11:22 pm	#5
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: B&O Beovision MX4000 defective Hi (Niko?) I'm glad you got your set going again. That fault was very common with that range of tubes and by no means confined to B&O sets. Very often that little board was quite badly burnt by arcing when the sets were left on with that fault.

12th Jul 2017, 3:50 am	#6
Maarten Dekatron Join Date: Dec 2007 Location: Haarlem, Netherlands Posts: 4,199	Re: B&O Beovision MX4000 defective Ah, I thought you already checked that ("on top of the tube", actually at the bottom here but on top in most models) but you probably meant the crt connection board.

11th Jul 2017, 12:10 pm	#4
nikosyr Retired Dormant Member Join Date: Jul 2017 Location: Tampere, Finland Posts: 2	Thanks ukcol! It's alive! https://drive.google.com/file/d/0B49...w?usp=drivesdk https://drive.google.com/file/d/0B49...w?usp=drivesdk Here's game picture https://drive.google.com/file/d/0B49...w?usp=drivesdk