Hello all,

I got a MX6000 for free because it used to shut down after a few minutes. With the help of this forum I have been able to repair it, and it has played for two weeks without any problems. It is a very nice TV set. But now it has a blurred picture during power up for some time; it's like it cannot synchronize. After some time the picture is OK and stays OK. It only appears on analog TV input mode, the picture is OK when I use the digital tuner on AV2 or with DVD. I assume the problem is on the PAL decoder board? 

Is anybody familiar with this problem?

Thank you in advance.

Regards,

Bart.

Hoi Bart,

By blurred do you mean the picture is stable but there is ghosting?

Are the digital tuner and or DVD set to RGB or CVBS output?

If it happens with CVBS from both the tuner and SCART then it could be dry capacitors or a dry/cracked joint on the PAL decoder board or the video/sound switching board.

If it only happens with CVBS from the tuner (i.e CVBS through a SCART is always ok) then it could be the tuner or possible the video/sound switching board, I would need to check the diagram...

Richard

Hi Richard,

By the looks of the picture with B&O logo by your name, I'm quite sure we met yesterday.

But to get back to the issue; no, the picture isn't stable. It's not synchronizing and the colors aren't stable either. After about half a minute, the stable picture gets through and it stabilizes and after that it is OK. But this wasn't the case the day before yesterday. 

Both DVD and digital tuner are connected with scart; DVD on AV1, tuner on AV2.

Regards, Bart.

Hello again Bart

The internal settings of the external devices is important.  Most DVDs and STBs allow you to select either RGB or CVBS (composite) as their method of output on SCART.  If you select RGB then the signals take a different path on the video/sound switching board and completely bypass parts of the PAL decoder.  If you select CVBS, this signal will take the same path as the analogue tuner from the video/sound switching board. 

If you only see the fault with the inputs from either the analogue tuner or from a SCART fed with CVBS but not from SCART fed with RGB, then the problem must be around the PAL decoder or CVBS path on the video/sound switching board.

From your second post I would suspect capacitors.  There are not that many and once changed, they are eliminated.

Kindest regards,

Richard

Thanks for your help Richard,

I do think that both DVD and tuner are connected with RGB rather than CVBS. The DVD has CVBS connection on the front that I do not use. The tuner is a simple Samsung with no options of choice. Therefore I think that the SCART is used for RGB. 

It is very likely that you are right about the capacitors. Especially the fact that the problem appears with cold start only (on stand by there is no problem) looks like a power supply electrolyt capacitor that is bad. It looks like it takes time to build up the voltage across this capacitor and after that it is OK, as long as the TV is not switched off completely. 

I will start with replacing all electrolyts on the PAL board.

Regards Bart.