[spassmaker]

Hi Alf

The felt pad or whatever you took should fit not tight into the groove. Check if the idler runs nearly free when you spin it with the finger in both 33/45 RPM without motor. The size of the felt pad is critical, a little bit too big and it would slow down the idlerwheel significantly.

The stepped pulley is nice and clean?

Btw, had a knocking noise when the shaft of the motorchassis was hitting the speedselector shifter bar (part No.35).

The chassis has to be aligned that the shaft is in the middle of the gap. Have a closer look in this area. You can align it by turning the washers that hold the springs of the motorchassis.

There should be no contact from any parts to the main chassis.

Look page 13 of SM ( Beogram 1200) “the most frequent cause of motor noise, hum and rumble in the Beogram 1200 is defect in the mouning of chassis and motor……”

[spassmaker]

Hi

As far I can remember is that when you put 2 caps in a row you have to double the capacitance.

I would try two 47uF in row.    +–+

The brake circurit has to be checked too.

Check TR21 TR32 TR33 and the value and polarity of C 43

Let us know if you got any progress

Kind regards

Christian

[spassmaker]

Hi Alf

The brass tounge has to sit in the groove tha s right. At the tip of the tounge is a kind of feltwasher, sometimes missing.

Where did you get the “new” idler wheel?

If you got yours from Martin (Beoparts) the new wheel should run quiet. These wheels are made very well.

Did you mount a new belt? If not order one from Martin he provides the right ones  with the right specs. Do not buy any from E-B…. No orange silicone ring.

Hope that helps a little bit.

Kind regards

Christian

The things in the motordrive are working all together.

[spassmaker]

Hi….? What´s your name?

There are different versions of motors in the Beogram 1000.

Rectangular motor housings like Beogram 1200 have a conical stepped drive pulley where the speed is regulated via the smaller knob at the speed selector. The motor axle is lifted or lowered via a plastic gear underneath the motor.

Motors with a round housing have a straight stepped pulley where, a so called “Eddy Current Brake” is implemented. The brake does what it´s called, the motor runs without brake too fast and you have to adjust (lower) the speed with the same smaller knob at the sped selector.

Often this knob is seized from hardened grease and has to be disassembled, cleaned and oiled again.

A picture from underside of the Beogram without lower wood cover would help.

Indeed these Turntabels have to be renovated after abou 50 or 60 years.

Fresh oilinfusion for the bearings or some new Bearings from Beoparts.dk would help, but you have to know what you need so have a look inside.

 

Kind regards

Christian

[spassmaker]

Hi Mike

Send me a PM, I’ve a 3d printable .stl file for you.

Kind regards

Christian

 

[spassmaker]

Hi

First hitting and bumping these amps seems not a good idea for a repair ;-))

For me it sounds like a cold/broken solder joint.

You said that all sources are involved so there seems to be a problem in the output section of the tonecontrol or the input of the poweramp.

Look for the tonecontrol PCB 3 there are all sources connected and the output to the

poweramp PCB 9.

Look at the output connectors PCB 3  and input connectors PCB 9 for cracked solder joints.

If necessary resolder them, but disconnect from mains before you start, I can tell you: do not solder in a runing amp and don’t ask me why I know this:-))

More BANG than Olufsen

When you change the volume with no source connected is some crackling audible (VOL Pot)

The other problems you discribed seem to have another source on the uPC PCB 2.

There are a lot of connectors which can come loose from hitting and bumping or even cold/ cracked solder joints.

These cold solderjoints are a common problen on these and other B&O gear of this age, but not only related to B&O gear ;-))

Is the poweramp cooling fin getting hot?

The fins should stay handwarm even after 1 hour idling with no signal.

The cooling fin of the power supply PCB 16 are normal gettin hot about 45 to 50 Celsius.

Did you alredy recap the PCB’s (PCB 9) and did you renew the trimmers on the poweramp PCB?

Did you adjust the no load current and the offset of the poweramp?

Only a few hints…let us know if you had progress.

Kind regards

Christian

[spassmaker]

Hi Adam

Maybe there is a 2nd counterweight missing.

If you look on page 4.3 in the SM Beogram 3400-1900-1100 there are two of them.

1 the one you mentioned Part  Nr 52 Counterweight

2 that maybe missing       Part Nr 63  Counterweight

seems it is connected to   Part Nr 60 pointer ( slider)

Kind regards

Christian

[spassmaker]

Congrats, issue solved

 

 

[spassmaker]

Hi Alf

Do I understand right? You are measuring 6 V at C of 1TR 20 and 2 Volt at SI on the mainboard?

If so it seems that you have a broken trace between these points.

SI is connected to several IC’s on the logic board under the button plate.

Have already had broken wireconnections b etween mainboard and logicboard, maybe you have a closer look there.

Kind regards

Christian

[spassmaker]

Hi

In between the speakers moved to my livingroom and I’m sure that I don’t need a subwoofer anymore. In this moment they are connected to my Denon receiver with all tonecontrol turned off and the sound is very impresive, nothing is missing, no boomy bass just controlled but very deep.

The adjustmentscrews for tilting the speaker were too long, cut them about 25 mm and now the speakers are tilted in a for me good looking way.

The Beomaster, Beogram and Beocord will come the next week into business.

In the moment i don’t really see the MC 40 cabinet in my living room, in my taste it’s too high (about 63 cm) plus the Beomaster 8000 on top, together nearly 80 cm.

Maybe someone could make me an offer for a Cabinet SC 80-2 ;-))

Now to the fabric.

I started with gently prying out the aluminiumtrim, possibly with not bending too much because the corners are cut to 90 degrees and only a tiny part of material is left on the edge.

Two corners were broken during disassembling ;-((

I pryed off the old fabric and tried with a smal part of the new fabric to get it into the frame and push the aluminiumtrim in to clamp the fabric in place.

No chance, the fabric seems to be to thick.

I had a closer look to the original mounting of the fabric and could see that the fabric is only bent around the edge to the slot where the aluminium fits in.

The first attempt just to spray some glue on the frame and pull the fabric in place failed because you glue to the front and the fabric comes to a wavy looking on the edges.

After a bit headscratching how to get this done I decided to prestretch the fabric on my table with some staples like in the picture below. (Fabric face down, staples about 35 X 30 cm)

The pattern is caused by camerasolution.

I masked the frames with painters tape to get the sprayglue only to the front and the edges:

waited about 2 minutes to let the glue getting sticky and pressed the frame to the fabric.

Than I took a  square profile weling wire of 2,5 mm and cut  with a razorblade a straigth 2 mm excess.

This excess cam be layed around the edges and pressed into the still sticky sprayglue.

After that the aluminium trim could be reinserted snugfif and looking good.

The broken corners of the aluminium don’t matter, hardly visible from 1 m distance.

Did not take further picture yet, comming soon.

Kind regards

Christian

 

[spassmaker]

If you really must have a video, here it is:

[spassmaker]

Hi

First, F1 is blown because D20 was shot.

D20 is a protection Z diode wich makes a short circurit to ground when the voltage rises above e.g. 6,3 volt to protect the uPC.

I’m not really sure but for me it looks like the reset IC1 PIN39 should have low level.

I would recheck TR17 and C20 and D15.

Maybe member Dillen has a suggestion about the reset state at IC1.

BTW:

Did you recap the Beogram or did you resolder the solderjoints of all plugs so far?

Lot of trouble comes from these failured caps and dry solderjoints.

Kind regards

Christian

[spassmaker]

Hi

The problems you discribed are mostely caused by the rotten foam inside the speakers.

There is a PCb in the lower section of the speaker with the relay circurit, the most lower copper traces can be solved by the rotten foam and must be renewed with e.g. some wire soldered to the start and end solderjoints.

Further information about disassembling you can find here:

Beolab 8000 preventive care.

Look for these traces:

Any questions? let us know.

Kind regards

Christian

[spassmaker]

As I already wrote, the speakers sounding absoloutely amazing.

Far different from the M 150 of course more deep bass.

Have the MC 120.2 in another room, did never expect such a good fundamental sound, missing nothing.

Next day I hope to compare with my Nubert Nuline 102. It´s not a real comparison 😉

Now it´s time to say goodby to my 5.1 set and switch back to stereo with Beomaster 8000, Beogram 8000, Beocord 9000, Beovox MS150.2 and a MC 40 cabinet.

Maybe I connect a pair of CX 100 to the secondary speakeroutlets to have a “rear speaker”.

Have a nice week

Christian

[spassmaker]

Hi

What I would do is to open the amp again and have a close look where the tabs should go.

Maybe a part of the wireharmes in the way.

The shielding plate over the uPC is in it´s place and all the way down? All metaltabs of the plate are outside?

You could stand the amp like an open book on it´s side so you can better see and feel what going on.

Put somthing under the amp to not damage the wooden frame.

Usualy push from below in direction of the display and push down the lower edge and let it snap in.

Regards

Christian

[spassmaker]

Hi, here are some news…

I cleaned the wood with a magic eraser and a light soaped water with a neutral soap.

After letting it dry I put some renovating oil on the wood and let it shine again.

I recapped the Crossover network with new bipolar caps, just business as usual, old ones out new ones in.

After that I assembled the chassis into the front frame and made the wireconnections to the speakers.

Mounted the frame to the speakers and made a testride.

Wow that sounds absolutly amaizing.

Here is the not really finished speaker,  fabric was not delivered today  😉

 

 

[spassmaker]

Hi

Yesterday the foam surround from “Good Old HiFi” NL arrived.

So I started to refoam the 4 woofers.

First I started with the 8″ woofer, cleaned the cast frame and carefully sraped the old glue from the plastic cone. My favorite solvent Mellerud glue remover made a good job.

Before:

After:

After cleaning I glued the foamsurround as much possible centered to the cone. I’ve made a marking arround the cone to see how far the glue should be painted. Put the glue to the backside of the inner foam let it dry for about 5 minutes and pressed it firmly to the cone.

After that I clamped the outer foamring with clothpins to the frame and made a test with a conected amp and my mobilephone and the “Tonegenerator” app at 25 up to 50 Hz to hear if the voicecoil is aligned an centered. No adjustments where requiered. The 8″ woofers need no chimming in my case and I glued the foam to the cast frame. You could see on the last picture.

Up to the 10″ woofer.

I started with glueremover very carefully only on the old rotten glue because the cone is made of paper and I would not to get to much moisture into the paper.

After about 10 minutes I could peel off the old glue with my fingernail. There is a minimal layer of paper wich comes off with the old glue but that’s no problem.

As you cn see there is a damage left from the stick wich was mentioned in the first post. The new foam surround covers exactly thes damages so I’m happy. ;-))

Next was the same steps as the 8″ woofer, I glued the foam to the cone , tested with clothpins and made a marking around the outer foam to know where the foam has to be glued on the frame.

The cone centered itself like the 8″ woofer, no alignement nessesary.

Here is the result:   cheers;-))

Complete set of woofers after 5 hours:

Thanks for watching!

Next is the renew of the fabric grilles, new capacitors on the filterboard and refreshing the wooden case.

Kind regards

Christian

[spassmaker]

Hi

In between I dissassembled the 8″ and 10″ woofers from the cabinet.

The coils are measuring all good so far.

I decided to bring them back in shape as following:

Took some aluminium profiles 10X10 mm and put them underneath the cone to lift the cone upards about 1 cm above the metal frame.

Sprayed with a small amount of water front and back of the cone and let them laying cone downwards on the table over night.

The weight of the chassis gave the right amount of pressure to the cones and next day it looked very good for me.

on the picture you could see the result.

Does anybuddy have a good source for the front fabric? Mine have some small holes and not looking good anymore.

Still a little bit dirty but that will be no problem so far ;-))

Waiting for the foam surrounds…..

Kind regards

Christian

[spassmaker]

Hi

Thank you for the helpful hints.

For me it looks like the stick has left two dents in the paper cone while it was there for several years and I’m not sure how to bring the cone back to shape, maybe with hot steam.

I will take out the speaker next days, foam surrounds are already ordered.

I give more information after that.

Regards

Christian

 

[spassmaker]

Hi

Looks like the Beogram and the Beocord need some restoring.

Beogram: All capacitators, resoldering of contacts and adjusting the << >> buttons, new tangential drive belt.

Beocord: Most all capacitators and cleaning the cassette drive mechanism, new belts.

Ask for someone near you who has some experience with B&O gear.

Regards

Christian

[Author]

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