This is a common problem with this chassis,and is easily sorted if you can solder,and you are competant with the innards of telly's?There is  a thread on the site relating to this,where a member took some photo's too.

Nick

The old thread Nick refers to is probably this:

/forum/general-discussion-and-questions/bv7-scart

You'll need to adapt the information a bit, as the thread talks about the Unity 1 chassis, while MX6000/7000 are Unity 2. They are very similar though, and you can easily follow it with the MX6000 service manual (the good one we have is easiest to find under MX4002).

You have now a horizontal deflection fault, which may have been triggered by a bad solder somewhere or a typical failed cap / semiconductor. Probably very cheap to repair, but may take a while to faultfind.

tournedos wrote:

The old thread Nick refers to is probably this:

/forum/general-discussion-and-questions/bv7-scart

You'll need to adapt the information a bit, as the thread talks about the Unity 1 chassis, while MX6000/7000 are Unity 2. They are very similar though, and you can easily follow it with the MX6000 service manual (the good one we have is easiest to find under MX4002).

You have now a horizontal deflection fault, which may have been triggered by a bad solder somewhere or a typical failed cap / semiconductor. Probably very cheap to repair, but may take a while to faultfind.

There is also a thread for MX4000, MX6000, MX7000 and AV9000. 🙂

Take a look here. 

- Dennis

Thanks very much for the fast replies – much appreciated.

I had already found Die Bogenars workshop on the MX5500 and noted that it was quite different to the MX7000 that I was looking at.  However, I didn’t know that he had done another workshop for the MX4000 and 7000.  That thread is proving to be extremely helpful on this project.  Martin did a great job – yet again.

I have now got to the stage where the power board is out and ready for working on.  The amount of dust inside the unit was huge – not really surprising after 13 years.  I have vacuumed everything so that I can now recognize the components and read the labels.  So far, I can’t see any horrendous burn marks but maybe the problem has been caught early.

Next step is to get the replacement caps and check the diodes.  Then I’ll put the parts in and re-solder the board for good measure.  That looks as if it could be a big job.

Thanks again for your help and advice.

Regards

Geoff

When you've removed the "dust of ages",and "the dog can see the rabbit",have a look at the scan coils connector on the base of the crt.You will almost certainly find that the last pin on the right hand end of the connector is burnt.Carefully loosen the little pcb that the connector goes to,and check for a burnt connection behind it.Resolder the connection,or if badly burnt,bypass the connector and solder the wire direct to the scan coil termination.

Nick

It must be stressed folks that CRT's should not be attempted by anyone who does not have a good understanding of the high voltages used in this set - quickly looking at Die bergers thread seems to suggest that the 27kv voltage is the dangerous bit and implies the 400 or so volts in the reservoir cap could be a cause of trouble - well IMO the smpsu cap is by far the bit to be cautious about. I have had a few belts from the EHT side before (not while powered but shortly after) and they hurt like hell, and can throw you off your chair - but I would not want to touch a fully charged reservoir capacitor in the power supply, IMO certain death or severe burns at the very least!!!!

ONLY TRAINED FOLKS SHOULD EVER SWITCH A TELLY ON WITH THE BACK REMOVED!

Please take care Geoff!

If it were mine, I would fix it or have it fixed. There is no way I would part with such a beautiful TV. I hate modern TVs, absolutely characterless in terms of form bar BeoVison 5/9.

If I were ever to get back into watching TV in any capacity and could devise a way to get one of these sets to work over here I would have a white MX on its motorized floor or wall stand. Or for that matter, smack in the middle of the floor! No other way about it. 

Sorry to deviate from the course of this thread but I feel compelled to say this!

PS: Now here's a question for the pro's.. Were the MS versions sold stateside?

Thanks for all of the comments everyone, always appreciated.

Solderon29

I took some photos of the parts that I think that you were referring to.  The first was taken from the front where everything now looks clean and OK.  Can't seem to get that one to load up???

The second was taken at the back and there definitely looks like a bad joint at the back of the socket.  I can’t see anything on the fifth terminal but I will definitely have a go at re-soldering the second.  Just hope that it hasn’t burnt the contact pad away.

Well done and excellent advice – obviously the true voice of experience.

Olly

Safety advice is always welcome.  This is my first proper TV repair job – up till now, I have stuck to the radio, tape deck and turntable side of the business.  I’ve ripped open a few TVs to get some parts but I still have a lot to learn.  Normally, I leave the units off for a few days before diving in and every capacitor gets the screwdriver across the terminals.  So far, so good but one must never become over confident.

Evan

I agree that a tidy and clean MX is always a pleasure to look at.  Even though I now have two BV7s for general viewing duty, I cannot bring myself to throw the two MX7000s away.  They will be around for a while yet as long as they work.

Regards to all

Geoff

Yep,thats your problem.It's very burnt though,so I would bypass it as the plug/socket will be burnt too.Cut the wire where it goes into the plug,and resolder it direct the the terminal on the coil assembly.

Yes indeed,take care in there.The resevoir cap referred to is C9 on the main board,but it will discharge fairly quickly.

Check for dry jointed  C12 ,C102,103.Replace C100,C29 and C31,but otherwise "if it aint broke,don't fix it"

Super telly's,hope you can keep it going.

Nick