The Workbench

Re: Working on a Beomaster 4400

Dillen — Tue, 15 Feb 2011 01:40:17 GMT

I like the idea of repairing rather than replacing. It gives a certain rewarding feeling.
The challenge of having to come up with an idea is also welcome. Keeps your brain alive

Nice solution with the black plastic part at the backside of the slider, Sonavor.
I think, I would have drilled a 1mm hole and glued in a tiny steel pin next to the remaining post but your
solution will also work, I'm sure.
And nice work with the perspex, Geoff !

Martin

Re: Working on a Beomaster 4400

Søren Mexico — Mon, 14 Feb 2011 23:59:49 GMT

geearr:

Yes, a good supply of perspex offcuts in a range of thicknesses has made numerous contributions towards saving the life of an old B&O. The material is so easy to shape using files, fine hacksaws and of course the invaluable Dremel. For example, in the case of the Beomaster 3000, it is not unusual to find that the tuning cursor has lost 2 out of its 3 prongs. However, a small piece of perspex, hacked into shape and drilled with a hole to match the remaining prong can save the day as shown in the following photo. Very simple and effective.

Have fun and remember that there is always a solution somewhere.

Regards

Geoff

Amazing, will use it, a lot of possibilities, thank you

Re: Working on a Beomaster 4400

sonavor — Mon, 14 Feb 2011 23:42:46 GMT

Thanks again Geoff. That is really useful information for keeping these vintage stereos in good working order.

-Sonavor

Re: Working on a Beomaster 4400

geearr — Mon, 14 Feb 2011 23:33:55 GMT

Yes, a good supply of perspex offcuts in a range of thicknesses has made numerous contributions towards saving the life of an old B&O. The material is so easy to shape using files, fine hacksaws and of course the invaluable Dremel. For example, in the case of the Beomaster 3000, it is not unusual to find that the tuning cursor has lost 2 out of its 3 prongs. However, a small piece of perspex, hacked into shape and drilled with a hole to match the remaining prong can save the day as shown in the following photo. Very simple and effective.

Have fun and remember that there is always a solution somewhere.

Regards

Geoff

Re: Working on a Beomaster 4400

Step1 — Mon, 14 Feb 2011 15:17:50 GMT

plexiglas, acrylic glass... I would guess it takes a steady hand and perhaps tools like razer saws and files to make small objects...

Re: Working on a Beomaster 4400

sonavor — Mon, 14 Feb 2011 15:03:40 GMT

That's great information Geoff. I hadn't heard of Perspex before. Is it hard to cut into shape?

Re: Working on a Beomaster 4400

Step1 — Mon, 14 Feb 2011 04:26:57 GMT

Nice work Geoff!

Re: Working on a Beomaster 4400

geearr — Mon, 14 Feb 2011 03:09:39 GMT

I have done a lot of repairs with these sliders and the solution really depends on how extensive the break is and where it is.

This first example shows one of my dismantled sliders and illustrates how one of the lugs on the slide was simply re-formed with epoxy. That is a fairly straightforward repair but sometimes the two lugs can be very fragile and might break again depending how often the slider is used.

My second example shows the situation where not only the lug on the slide broke off but also the pin on the cursor plate itself. In that case, I fully re-formed the slide and got rid of the two lugs altogether. This gives a much stronger repair on the slide. I then cut an intermediate shape out of Perspex and the photo shows two of my early attempts – they tend to look a bit neater later on after a lot of practice.

In the last photo, these parts are assembled and there is a very strong joint between the slide and the cursor plate.

Some ideas that you can consider.

Regards

Geoff

Re: Working on a Beomaster 4400

sonavor — Sun, 13 Feb 2011 22:52:29 GMT

Thanks for the suggestion. I didn't have any small nylon screws available and already started on a different option.

I ended up taking some hard plastic packaging that a screwdriver I purchased came with. There was a hole in the packaging that was used to hang the screwdriver in the store. I cut out a square around the hole and attached it to my balance slider control using super glue. So I was glueing a nice area of plastic to plastic. Before I glued to two pieces, I removed the balance slider pot and took out the plastic slide piece that had the single post. I used that piece as a guide to make sure I left enough room between the white post of the balance slider and the edge of my plastic packaging piece.

I have attached a picture to show what I mean. While I had the slider plate off the 4400 I went ahead and cleaned all of the slider pots with deoxit. The front plate is now back in place and the balance slider now works.

Re: Working on a Beomaster 4400

Søren Mexico — Sun, 13 Feb 2011 22:21:42 GMT

Drill a 2.5 Mm hole where the piece has broken of, cut 3 Mm threads and insert a 3 Mm nylon screw.

Re: Working on a Beomaster 4400

sonavor — Sun, 13 Feb 2011 19:44:22 GMT

After studying the 4400 with the top cover and bottom cover off I realized the B&O engineers left a tiny path from the underside where a small screwdriver could go in at an angle and remove the two inner screws that hold the slider control bar to the faceplate. I was able to remove the faceplate and check out where the balance slider isn't mating with the balance slider pot. NOTE: The tuning slider snaps to the plastic piece that is glued to the tuning pulley string. I have attached a picture of the disassembled unit with the balance slider pot pulled out. You can see that there should be two small, square, black plastic posts that form a notch where the slider button fits. The balance pot has one post broken off. I will have to figure out how to rig up something to attach the slider pot remaining post to the slider button (without glueing them together). Any suggestions?

Working on a Beomaster 4400

sonavor — Sun, 13 Feb 2011 18:28:26 GMT

Hi, I am new to this forum. I joined because I like B&O products. I bought my first one, a Beogram 4000, way back in the seventies. I now own a couple of turntables (Beogram 4002 and 8002), several Beovox speakers and an old Beocord 5000 (that needs repair...another story). I recently purchased a Beomaster 4400 receiver. I always loved the styling of that piece so I found one at a reasonable cost. It isn't mint by any means. There are some scratches on the front bar where the slider controls live. The seller thought this unit didn't work in both channels and wanted to get rid of it.

I have opened the unit up, cleaned everything I could easily get to (it was pretty dirty) then tested it. I was surprised that it came to life and one of the channels did indeed work. For the music source I just connected an ipod to the tape 1 playback. On investigation of the channel sound problem I discovered that the balance control was not connected to the balance pot. The balance pot was all the way to one channel. I used a small tool and moved it back to center and I now have sound in both channels. The next test was to check the tuner. I connected a 75 ohm coax from my antenna and the tuner works great. I have also checked both speaker connections and the headphone jack. All appear to work fine.

So, I appear to have a decent working Beomaster 4400. My next step is to try and fix the problems with the control bar that has the slider controls. I might try and repair the scratches but my first choice is to repair the balance control. The bass and treble slider controls have a loose aluminum piece on the actual slider as well. That means I need to remove the slider control bar. I have the Beomaster 4400 service manual. While it shows an exploded view of the mechanical parts, it doesn't say how to disassemble the 4400. I can see that there are four screws from inside the chassis that are attaching the control bar to the front face of the 4400. However, the angled face of the unit makes it impossible to get a screwdriver on them. Did B&O techs use a specially made screwdriver for removing the control bar? Or do I need to remove other pieces first? Once concern in doing this repair is that the main FM tuner control is attached with glue to the tuning pulley string. If I am able to loosen the four control bar screws I will have to be careful not to break that.

My question to the forum is if anyone else has removed the control bar from a Beomaster 4400 and what the proper steps are?

Thanks,

Sonavor