[Die_Bogener]

It is possible to remove the glass panel … 1 bolt on the side. It’s a push and lift construktion…

… and then you see the rubber contact to the glass panel. Or is it missing? Touch and start.

Never touch the glass inside… NEVER!

[Die_Bogener]

Measure the sound source device to the beolab input. Without the RCA cabel connected.

Some houses use different power installations… and have problems with the 220V power distribution. Sometimes there are some hundred Volts between the power plugs.

Soooo, use ONE power plug for all of the hardware you use. Connect Beomaster, Beolab, all sources and loudspeaker with ONE power plug in the wall. And disconnect the antenna…

 

I had a BC9300 here with 190V Antenna to ground …making a spark when plugged in ! And when touched making a gribbling hand…

[Die_Bogener]

Die 4000er braucht den Schaumstoff nicht, auch die 2500er nicht… da mache ich ihn komplett raus. Ich bemerke auch keine negative Klangänderung davor/danach…

Nur die 6000/8000 brauchen den Schaumstoff dringend, sonst atmen sie hörbar durch den Bassreflexkanal… aber nur als Trennung Verstärker/Lautsprecherraum und rund um den Kanal. Der Rest ist unnötig.

Geiles Zeug, gell? Hilfreich sind ein paar Gummihandschuhe und ein Eimer oder Wanne zum Wegwerfen… der Rest geht mit Isopropanol vom Innenleben wieder ab. Das Schaumstoff Zeug ist überaus ätzend, es bildet Tröpfchen und zersetzt punktuell die Leiterbahnen der Platinen.

[Die_Bogener]

I have a pair of these early 8000 beolabs. They are still working perfect.

The difference to later models is: the rubber is not glued ON the cone, the rubber is glued BEHIND the cone… what looks better.

The problem is: you dont see if the glue fails and splits rubber/cone and you can hear it breathing. Also the linear control of the cone fails and rubs on the coil… scratching mechanical sound…

I have seen some of them with this fault., very often on Beolab 2500. A reglue of the rubber solves the problem… what is difficult on these 8000 woofers. You need a very, very  liquid glue mixture… the original Latex glue is waterbased and can be used with little bit more water.

[Die_Bogener]

Wenn solche Arbeiten kein Problem sind, ist es nur etwas Zeit… das Material ist preiswert…

 

 

 

[Die_Bogener]

Die Redline klingen hervorragend dazu… schon 2x so gemacht. RL60 passen perfekt dazu.

Nuuuuuur: die RL sind allesamt uralt. Die Weichenelkos sind fix&foxy und viele Membranen ebenso, meist ist auch der Stoff sowas von hinüber.

aber in gutem Zustand und gemacht sind sie erstklassig geeignet. Und sie gehören an die Decke…

[Die_Bogener]

Es kann die Gleitschiene sein, die ist normalerweise mit einem weissen Teflonfett geschmiert. Aber auch die dahinter liegende zweite Schiene sollte etwas abbekommen, die hebt und senkt den Tonarm.

 

Wesentlich wahrscheinlicher jedoch ist die Umlenkrolle vom Seil… auf dem Bild etwas vom Tonarm verdeckt. Die läuft gerne mal trocken…

 

[Die_Bogener]

Have you made the 220V- 240V modification? 10% more or less power…

[Die_Bogener]

Press “Mute” in Standby on the keyboard… and a light will go on.

 

A converter deactivates the Powerlink.

[Die_Bogener]

Check the 7805 power regulator… there musst be 5V. These 5V switch TR5 on.

And test 92 R1 !… it could be a thermal resistor inside the transformer.

[Die_Bogener]

Your phone is isolated to Ground and to the 240V power.

RCA from somewhat else as a sound source is not isolated, it can have voltage to Ground. Sometimes very high voltages… i found already antennas with 190V (!!!)

Measure before plugging in the RCA the voltage between source and 8000. Measure ground to ground and signal to signal. There will be some voltage. Use DC and AC (!!!)

Use 1 (!!!)  multi power plug/cord for source and 8000. Then the voltage should be gone.

If gone, your house installation has a problem.

 

[Die_Bogener]

Have you ever seen this BC working? With your own eyes or ears?

Are you the owner? Or bought it later? With unknown defect?

OK, start again.

Call it transformer. If you connect the transformer to the regulator power board it blows the fuse.

Easy. Connect a regulated powersupply instead the transformer to the regulator board.

Maybe one of the 4 diodes of the rectifier have blown. Or C3 2200uF has a short.

But if the BC could be working in Standby  and reacted to keys… and then it blew the fuse: C6 10uF is dead.

Were any caps already replaced? In the correct polarity? A cap in wrong position will make you have a nice day…

 

[Die_Bogener]

Disconnect the drive… and use the bulbs to save money.

[Die_Bogener]

Put a 12V 5W light bulb … or 2 of them inline … in the overload line. Replace the fuse with the lights.

If you have a light, then there is a problem.

I told you, that the motor has caps inside (!!!). Check it.

[Die_Bogener]

Maybe a good idea… replace this smd c(r)ap with something more reliable…

[Die_Bogener]

The jumper determines left/right. So you can check loudspeaker versus BS2500…

[Die_Bogener]

Solder it.

Hum is just some millivolt.

Copper, mixed with chromeplated steel and nickel will always make some chemical noise.

You can also make a special shortcut plug for testing. Just a shorted Cinch connector.

Then you can test wether there is still humming…

[Die_Bogener]

chartz wrote:

There is no quick fix, unfortunately. Check the treble amp, its level trimmer, and the wiring too.

Confirmed.

But even if it was playing louder (level trimmer wrong…) it would not fail so easy and blow the tweeter… there is more. Tweeter fail because of a DC offset on the signal.

Check for DC direct on the tweeter.

And it would make sense to connect a small 12V bulb parallel for testing. It would show the fail of the amp if glowing.

[Die_Bogener]

The aluminum is eloxated. Very hard oxyd. Cannot be painted, no paint will stick on this oxyd. It will chip off easily…

You have to grind it, better is sandblasting with glas, not sand or steel.

As mentioned right before: you need a etch primer, then aluminum can be painted.

On the etch primer you can use almost every car paint… 2K.

[Die_Bogener]

All dead? No. Never. The power supply has absolute not enough power for this…

… and this area is always dark, quite normal.

Dead resistors look quite different. They are black and exploded… and not a bunch of them. Usually there is 1 (!!!) resistor working for a fuse.

Looks the same and working…

 

[Author]

Posts