[spassmaker]

Hi

The hint with loose connections is right, bad solderjoints are often found in these mashines too.

For me the display shows the typical symptoms of uPC controller is not workink proper.

Often this is caused by bad capacitators specially C35 10uF at the 5 Volt regulator 6IC4.

If you are handy with a soldering iron and have at least some basic electronic skills you could solder a new one in.

Before you are opening and working on the Beomaster always pull the mains plug from your AC outlet!

As you are working on the 5 Volt line for the uPC always think about ESD!

The cap is mounted to the legs of 6IC4, right side of unit on the heatsink mounted to the chassis, and easily to renew.

Next would be not as easy to acsess:

9C85 22uF this one is also a filtering cap for 5Volt line in the uPC housing can.

 

Kind regards

Christian

[spassmaker]

Hi

For me it seems that the current limmiting circurit 1TR9 and 1TR10 is always on, or the Darlington Transistor 1IC4 is not working proper.

I would look for all 3 transistors maybe just put some new ones in, sometimes they mesured as good with a DMM but don’t work because of lack in HFE.

Important to control or renew is 1C23 (100uF). If this cap has not enough capacity it will put the curent limiting circurit on too fast so that the solenoid can’t engage.

Regular transistors will work e.g. BC 547 cost only a few cents.

Darlington should be at least a TIP125.

Let us know if you got any progress.

Kind regards

Christian

[spassmaker]

Hi

As Martin mentioned the best way to get the Beogram back to “normal” operation is a total recap.

“STOP” and “ES” (End Switch) are causing the arm traveling faster than just pressing < or >.

There are two potentiometers for the slide transport 1R61 and 1R62 which can be adjusted for the traveling speed while pressing < or >.

Regarding to the service manual there is a plot underneath the Motor OM2 what measuremenst or voltages should be adjusted in all cases:

ON >>

<< OFF

<

>

So these potentiometers should be renewed as well, same for all other potentiometers, they tend to corrode and are hard to adjust to specs.

Let us know if you got any progress.

Kind regards

Christian

[spassmaker]

Hi John

If you’ve made the uPC TEST with in STBY Mode pressing MONITOR and STBY Button simultaniously and the display shows “TP” that means Test Passed so the uPC is in working order.

If there is any error detected during the TEST the display would show TE (Test Error) 1 to 13 depending of the detected error.

Is there any noise in the speakers like humming or white noise if you crank up the volume?

If not I would do following:

Often the speakerswitches are corroded or not working properly.

Check if they are switched to the “ON” position ;-))

Maybe toggling the switches bring them back to life.

Connect a audiosource to “TAPE IN 1 or 2”, key TP1 or TP2, try both, there are different ways through the audio switches IC’s

Check the Amp with a headphone conected.

The headphonejack is connected to the poweramp section with a voltage divider and no switch is between.

Let us know your results.

Kind regards

Christian

 

 

[spassmaker]

Hi

I’m not shure but maybe into the gap on the toothed levelarm above the last theeth and then a little right.

Regards

Christian

[spassmaker]

Hi Alf

Sorry maybe we missunderstood…

and Sorry but I ran in a wrong way to say that the 23.x voltage should be present after connecting mains, not right

The voltage is caused by 0 volt at P48-4. Comes from uPC PIN14 “ST BY”

As you wrote:

the voltage at 6IC9 – collector is about 23,x VDC – have not yet checked 6IC10.

I thought that you measured 23.x Volt at collctor of 6IC9.

Is the voltage on C33 and c34 ok? (about24V) also at Emitter of 6IC9 and 6IC10

but anyway there should be 5 volt at P48-4 and 5 volt at P48-5 in “St By” mode.

If you connect to mains there is a short “klick” right?

 

55 Volt are comming up when RL 2 is engaged, a short “klick” would not be enough to charge the big Caps c3 and c4.

The 55 Volt is used for the delayed relay circurit.

is the amp responding to any pushbutton?

[spassmaker]

Hi Alf

So if you measure 23.x Volt at 6IC9 there should be the same Voltage at P51-2 and at Relay RL2.

Measuring always with the same negative point.

Tis 23.x volt should be steady present after you plug the mains in.

The conection goes directly via P51-2 to the relay.

The other line to the relay RL2 comes from TR 18 via P51-1 to the relay.

Take a look for these connections and mesure at the Collector of TR 18

Check the voltage on P48-4 (ST BY) and P48-5 (RELAY ON)

Both should be LOW when the amp is switched on.

Regards

Christian

[spassmaker]

Hi Kris

If not already done, I would consequently renew all caps on the PCB’s.

The caps are comming to age sooner or later and loose their capacity, so there is a good chance to bring your turntable back to life.

Recommended is also to check and reflow the solderjoints of the connection plugs and sockets.

Ask member Martin at http://www.beoparts-shop.com for a capacitator kit and new belts for the platter and the tangential drive.

Regards

Christian

[spassmaker]

Hi Alf

If you connect to mains is the “red dot” in the display lit?

Where did you measure the 19.8 Volts? Direct at the Relay?

There is a voltage drop via TR 18 as well so there won’t be 24 volt at the relay.

19.8 V should be enough voltage to engage the relay anyway.

Is the voltage dropping to zero after you heard the relay working?

Had already bad connections from PCB 6 to PCB 7 check also for bad soldering or corroded plugs and/or contact pins

How is the voltage on Collector of IC9 and IC10 ?

Steady about 22 to 24 volt after switching “ON”?

Follow the schematic until you reach the CPU, check the whole way via TR11, TR12, TR18, P48-5, P76-6, R55, PIN16 IC4 for bad solderjoints or breaks.

Same for the POWER ON route via IC9, TR2, TR1, TR4, TR5, P48-4, P76-7, R57, PIN16 IC4

Did you already renew some caps? Here speacialy C35 10 uF on the 5 Volt Regulator right hand on the heatsink, often the reason for some trouble

Regards

Christian

[spassmaker]

Just send me a PM and we can share the. stl via Email.

Regards

Christian

 

 

[spassmaker]

I wish you really good luck and let us know if you got any progress.

Regards

Christian

[spassmaker]

Hi ” Matador”

I’d like to ask if you share the .stl file for the clamps.

That would be great ;-))

Kind regards

Christian

[spassmaker]

Hi

If you have checked and rechecked that the new transistors are the right ones and in the right place I would start here as Beolover does:

https://beolover.blogspot.com/2015/04/beogram-4000-cleaning-of-tone-arm.html

 

same here:

https://beolover.blogspot.com/2015/05/beogram-4000-restoring-slow-slide-transport.html

There are a lot of very helpful information related to the Beogram 400 on Beolovers site too, have a look.

Kind regards

Christian

[spassmaker]

Hi

The Strobe issue on the BM 8000 was just a misaligned Pot R15 which has to be adjusted to minimum ~3.6 Volt, the Pot was turned the whole way down and the CPU did not recorgnized the too small signal below 3,6 Volt.

This Pot is not present in the BM 6000.

If you can’t measure any strobe signal there must be something wrong with the CPU, I think, but maybe someone else has a similar experience with the BM 6000 and can help with a good idea or with a used and working CPU for a fist full of $

Had already 2 BM 6000 which I could not bring back to life because CPU related trouble. Doesn’t mean that the CPU’s in my case were really dead, but after working on these for days and not finding the error I made a decision to sell them for spare parts.

It hurts to give these iconic units away but…..

 

Sorry that I can help you further.

Kind regards

Christian

 

[spassmaker]

Hi

Sounds like there is an total recap service needed.

Don’t forget the 47 uF in the uPC Can.

Resoldering of all sockets ( pluigs) is also a good idea.

 

Kind regards

Christian

 

[spassmaker]

Hi Glitch

I’ve had a similar problem with a BM 8000 where the “SSTROBE” Signal wasn’t present.

If there is no STROBE no button and Displaywould work.

It’s only a small straw but maybe you check the Strobe Signal around IC 5 and the corosponding Transistors TR 15 – TR 22.

Kind regards

Christian

[spassmaker]

Hi

What I’d like to know is what orientation is the plug comming from the keyboard to the main PCB?

In my case the Red wire should look to the front of the turntable. Can’t see clearly in the video.

Only to be shure… ;-))

Where did you get this PCB with the 4 SMD Caps?

Kind regards

Christian

[spassmaker]

Hi

As you wrote that there is a white foam inside , it might be that teh foam was already renewed from a preownwer.

Could be that the old foam was not removed completely from the PCB’s and now the rest of the old foam did his work.

Inspect the PCB for unusual colours of the traces and parts.

Kind regards

Christian

[spassmaker]

Hi

You wrote that there is no ~30 Volt at the 4000uF Cap?

If you try to check the fuses,

!!! VERY FIRST PULL THE MAINS JACK !!! there is live voltage connected to the fuses!

I would check the fuses first, there are 2 of them in the black housing in front of the Transformator.

If they are measuring good close the black fuse housing and plug the mains back in.

Next I would check AC Voltage at P3 PIN 3 and 4.

After that check DC Voltage at P3 PIN 1 and 2 (4000 uF Cap)

Show us the results.

After that we look further.

Kind regards

Christian

 

 

 

[spassmaker]

Hi

The not responding << >> buttons might fail because of a defective Lightbulb in the pushbutton housing or a broken or loose connection between Main PCB and Pushbutton board (check first)

Often the wires of these Lamps are broken or the lamp itself.

Measure from backside of the buttonboard the lamps solderpoints.

If you measure “OL” the lamp is broken if you measure about 50 to 100 Ohm the lamp seems ok and the error is frome somewhere else.

Regarding to the SM Chapter 5-3 you can measure the Voltage of 620 mV of the LDR´s

( P 5 -4 and P 5 – 6) and try to set the voltage with the screws. If you measure about 1,5 to 3 Volt and you can´t adjust any voltage the Lightbulb is probably dead.

Let us know if you got any succsess.

Kind Regards

Christian

[Author]

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