A brave man - I take it you have dowmloaded the service manual and technical manual. There is also this

Thanks Peter

I have downloaded everything that is available and it does help a great deal.  The comments on BeoCentral are very valid and makes one wonder whether this is going to be worth the effort.  The amplifier board in my unit is certainly warped and copious amounts of polystyrene foam have been used to help with the isolation.

I have already found that the tabs on the output capacitors are badly corroded and very little AC is passing through them.  One of the amplifier channels may also be faulty too.  It all points to an expensive re-construction and given the shortage of rave reviews on the performance of this machine - I wonder?? 😕

Regards

Geoff

Geoff you must try to repair this stunning hifi! There are a few people whom have previously written that they like the warm sound of these hifis and they are very desirable to collectors...

I would do this as a slow-burn project if you are not overly keen.

Personally I cannot wait to get my hands on one of these! I don't think I would keep it, mostly due to lack of room...

I was lucky enough to get one in perfect working order. It soon became one of my favourites. Very eye catching and the sound in my opinion is very warm and pleasing. Its beautiful piece of design and there are less and less of them around. A big project I'm sure but definitely worth it!!

Thanks for the positive comments and I will probably keep going until I get it right – just because I like a good challenge.  I would also like to see if these machines are as visually impressive as they seemed in the old pictures.

I have now found that all of the large 5000uF audio cans have failed.  In two of them, the terminals just fell out (bad corrosion) when I loosened up that long train.  Now I have to find four replacements for those.  I put an old 4700uF can in one of the channels just for testing purposes.  The good news was that that channel finally sprung to life and at long last I have finally heard some sound from this unit.  Not the greatest but at least there was something.  Still, I now have a comfortable feeling that many of the boards might be working after all.

If anyone has any thoughts on a suitable replacement capacitor, I would like to hear them.

Regards

Geoff

Something like this? I have no idea where I got these, I've had a couple rolling on my desk for ages. Size 40 x 29 mm. If the size is suitable, at least you know that these exist somewhere.

tournedos wrote:

Something like this? I have no idea where I got these, I've had a couple rolling on my desk for ages. Size 40 x 29 mm. If the size is suitable, at least you know that these exist somewhere.

I have one, too. It's from Partco, and

look at the squared uppercase "M"

It IS a Panasonic 🙂

Although newer ones in 40x30mm seem to be 80Volt Types

  Gunther

Hi everyone

I have been doing some more work and research on this project and the current status is as follows:

Thanks for your input regarding potential capacitors.  In the meantime, I have been in touch with Dillen and he has offered to provide me with four capacitors that will be suitable for this task.  I look forward to finding out what he is going to send and one day, I will hopefully see how well they perform.

The output capacitors have been disconnected and I have done some more work on the signal paths under no load conditions.  It is now clear that the left rear amplifier has a major problem but the good news is that the other three are performing almost identically.  That gives me some solid references which I can use to assess the situation in the faulty amp.

I finally found a piece of suitable rubber tubing for making the connection between the volume control motor and the shaft with the clutch assembly.  Tests have shown that everything works well in this area and the variable volume is being passed nicely into the three working amplifiers.

So now, my new main problem is how to fix this amplifier??  I will start by trying to source three replacement ICs and the two transistors because I might as well replace the lot after putting in all of the effort to dismantle it.  But --- the most serious difficulty (which prompted me to start this thread in the first place)  is what is the best way to dismantle this machine for ease of access.  I can currently only raise the amplifier board about 10mm before it gets very tight and that isn’t going to be enough to work on it neatly. 

The good news is that I have now reduced the dismantling scope to some extent which obviously helps.  The front part of the machine is relatively easy to access and I have taken out PC14 to give more room around the volume module and the output capacitors.  However, I am finding it very difficult to access anything around the transformer, PC6 & 7 and the amplifier section

Has anybody carried out any repair work on the amplifier board PC11 and replaced the main ICs???  I would love to hear from you.

Regards

Geoff