No one has a suggestion here for how to proceed with this problem?  

This is a beautiful Beocord 9000 now sitting here absolutely useless.

Any and all suggestions will be most appreciated!

Thanks,

Jeff

Hi Jeff,

         have you narrowed the problem down to a defective motor? If so do you have the part number or spec's for it as I have a few miscellaneous motors from all sorts of vintage products hanging around.

Chris.

Hi Chris,

I replaced the motor with no difference.

The only thing that concerned me about the replacement motor it that it had an orange wire instead of a red one. (Orange, black, and yellow…. as opposed to red, black, and yellow.)

I need to check to see it power is reaching the motor….. something I should have done in the first place. However, my original motor was growling, so I “assumed” that no tape movement meant a bad motor.

Everything else works: the electronics are set to go and the heads engage briefly and then retract.

Jeff

Jeff:

2 places to check.... motor driver circuitry and drive transistor on actual motor.

These motors can also be dead. I've had to replace mine due to bad brushes.

 Most likely bad motor.

You can order new motor from B&O for about $40 bucks.

Derek

Hi Derek,

I purchased a used motor from a highly reliable dealer in St. Louis which came with the board still attached.

I was unaware that a replacement motor was available from B&O.

At this point I think I need to determine if power is reaching the motor.

Everything else is working properly, the heads engage, but the motor does nothing. Ditto the replacement motor.

Being an enthusiast, not a technician, any ideas where I need to be checking? I do have an excellent Fluke Multimeter…. I just need to know which points to check and at what value.

Jeff

Jeff:

get the 9000 manual from this site.

There are 3 wires to the motor.

1) ground. 

2) power (+12V? I don't remember)

3) tacho (it provides speed pulses)

Measure the voltage across power and ground (refer to service manual for test points).

You may only get the voltage reading for a few seconds and it may shut off. The reason is it expects feedback from the tacho sensor which if the motor isn't turning won't produce one.

 I think since the capstan is on all the time with these decks even when idle, that this is probably why the motors all die sooner than later.

Derek

Derek:

Hopefully I will have the time on Sunday to check things out properly.

I have the Service Manual.

Absolutely everything works except the motor. I suppose it is possible that I purchased a “bad” used motor. It could happen.

However, I really need to determine if the replacement motor is getting power.

Also, does anyone know if the wire color is all that important? The original motor had red, yellow, and black wires. The replacement has orange, yellow, and black wires.

Jeff

Of course the color is important.

By convention red is power, black is ground, the third wire is the tacho.

But double check by reading the schematic. A good place to start is to look at the transistor that's mounted on the motor assembly. It should be obvious which wire is which even if the wire color is different.

If the fuse blows it means that there is power to the motor no?

Unplug just the motor from the circuit board and power up. You should get a voltage across the fuse and ground.

So what's between the fuse and the motor? Check the schematic, I think only a transistor maybe a resistor. 

Either your motor is bad, or the the transistor is shorted or both.

Get a new motor from B&O, they are around $40US. While you are at it change all the belts. You can order from Atlantic Systems.

Derek

Hi Derek,

The fuse blowing indicates that there is power available to the motor, yes.

I purchased a used motor with the transistor panel still attached. This is far easier to install. However, the same thing happens with the new motor and circuit board, the fuse blows the second the heads engage. This is what happened with the original motor.

So two different motors with circuit boards, but the end result is the same, a blown fuse.

Everything else still works. The electronics are ready. Press GO and the 9000 expects the tape to advance, but it doesn’t.

The heads engage over and over again, but retract when there is no tape movement.

I am confused.

Jeff

Seems to you me you have too many unknowns.

1) Did you do as I suggested: remove motor, power up and see if fuse blows? Can you measure a voltage across the output?

2) How do you know that the used motor is good? Don't rely on someone telling you; check it out for yourself.

Put together some batteries (assuming that you don't have a power supply) and see if you can power up the motor independently (maybe a 9V). You can also use an AC Adapter, 6-9 volts or so should do it. I can't remember the voltage on the motor.. it's not critical you just need to pulse it to see if it will turn.

If the motor isn't even turning before the fuse blows... I suspect bad motor or transistor or both.

In general you are looking at eliminating the variables. Either its the motor or the motor driver or both are bad. The sooner you cross one off the easier it will be.

Also check that the motor is wired correctly ie wires go to the right place on the molex connector. (compare with existing motor).

All of this of course takes time and patience. If you like going to casinos, a new motor for $60 is not a bad crap shoot considering how much you are paying for fuses.

Derek

Hello Derek,

I did as you suggested and I am beyond embarrassed as I tried powering up the original (now removed) motor that I believed to be bad using a 9v battery and it works just fine.

The replacement motor possibly could be bad, but I very much doubt it as it was supplied by Bill Rapp who is extremely thorough and dependable.

The Beocord 9000 had made a considerable growling noise when the motor was running, so I assumed that when it failed to play that the motor had failed, not an uncommon occurrence.

So what I have is a Beocord 9000 with all its electronic working properly, including when plug it in, two red LED’s light up briefly and then one remains on as long as the unit is plugged in.

The heads engage repeatedly every time the play button is pressed and then quickly retract.

However, if play is selected with a good 250mA fuse in place the fuse blows instantly.

This is exactly what happened with the original motor and keep in mind that I did not merely exchange motors as the replacement came with its transistor board attached.  

Does this tell you anything?

Jeff

Jeff:

You still haven't answered:

1) Does the fuse blow when you power up and hit play with the motor REMOVED.

2) If it does not what is the voltage reading at the output of the fuse

How are you testing the motor? Are bypassing the transistor when you are powering through the battery?

Did you test the Bill Rapp motor also with battery? Does it power up?


Derek

Hi Derek,

I will be more than happy to answer all your questions, however; first do you know the correct value for the fuse that lies directly under the cassette assembly and motor? This is the fuse that blows when PLAY is pressed.

The fuse that was in place was a 250mA 250v fuse. I have it under good authority that there are no 250mA fuses in the Beocord 9000 and that it should either be 850mA fast blow or a 600-700mA slow burn fuse.

If somehow the Beocord 9000 has the incorrect fuse, there is no reason to test for anything else until it can be established what the correct value should be.

However in answer to your questions:

1. No, I have not removed the replacement motor…. yet. So I don’t know if it would blow the fuse. Again, I first need to know if I have the right fuse in place.
2. I can’t answer this until I perform the above.
3. I tested the original motor by placing the black wire (now removed) and the red wire (also removed) to their soldier points and attaching the other ends of the wires to a 9V battery. When the battery is connected the motor runs briskly and quietly.
4. I regret that I am not technically savvy enough to know if this bypasses the transistor which is in place on the board where the solder points are. I am guessing the answer is no.
5. The replacement motor from Bill Rapp is in place in the Beocord 9000. I do not wish to remove it until I clear up the question of the correct fuse value. If an 850mA fuse is required it is clear that a 250mA fuse will blow time and time again, as it can not handle the draw when the motor engages.

So Derek or anyone else for that matter who knows the correct value of the fuse located directly beneath  the cassette assembly/motor, please let me know. Thank you!!!

Jeff

Jeff:

The correct value is located in the service manual. I seem to recall 250 mA.

 850 mA is awfully high for this kind of motor. The current from a 9V batter is about 90 mA.

 You can prove it to yourself with your spiffy Fluke meter. Put it in current mode. The meter of course will need to be placed in series with the motor not across the batter.

 Derek 

Derek:

I believe that there has been some error in my information regarding the 850mA fuse value.

I checked the two fuses which I removed from my Beocord 8004 as well as the Beocord 9000 and they are identical 250mA fuses with brightly colored stripes on them. I replaced the blown fuse on the Beocord 8004 and it works perfectly again. (I was attempting to adjust the motor speed sans the proper tool and blew the fuse.)

So I would imagine that the correct fuse value for the Beocord 9000, is as you said, 250mA.

So that begs the question why would the fuse keep blowing if the original motor was OK in the first place and the replacement motor came with the transistor board attached, yet nothing has changed? I keep blowing fuses.

I need to see if the replacement motor powers up when pressing stop, which will end the standby mode. I tried to check late last night with the cassette assembly in place, merely listening for the sound of the motor running. Today’s test of the original motor proved that it is absolutely silent, so I need to go a bit further.

Now that brings up yet one more question. If indeed the original motor runs silently (as it appears), what could possibly have been the source or cause of all that growling when the 9000 was in the standby mode? No tape movement, but so long as the motor was running in standby, it snarled.

I think I am becoming more befogged than before.

Jeff

>So that begs the question why would the fuse keep blowing if the original motor was OK in >the first place and the replacement motor came with the transistor board attached, yet >nothing has changed? I keep blowing fuses.

I refer you back to post 154952 of this thread.

Derek,

Point taken. I will try your suggestion to remove the replacement motor and see if the fuse still blows.

It has been suggested, among other things, that I try a 500mA fuse to see if that solves the problem.

Do you see any harm in trying this first?

Jeff

Jeff,

1) If the motor will run on a 90 mA 9V battery what makes you think changing the value to 500 mA will help?

2) Fuses are there to protect the circuitry and very smart Danish engineers select the appropriate values accordingly. If during a fault, fuses do not blow, then something else does and usually that's more catastrophic and expensive to fix.

Derek

Derek,

The advice to try a 500mA fuse came from a highly respected B&O repair facility. However, with all I know to date, I completely agree with you. Something must be wrong and to bypass the fuse protection is to risk doing even more expensive damage.

Here is the latest on the Beocord, and I believe it significantly narrows the potential problem areas.

Plug in the Beocord 9000 and two LED's light up briefly and then one extinguishes, the other remaining permanently lit while the 9000 is plugged in.

With a 250mA fuse in place, in standby, no problem. Press STOP and the motor moves the belt about 5mm and the fuse blows. I tried replacing another fuse pressing reverse and the same thing happened, the motor briefly moved the belt and then the fuse blew.

Once the fuse is blown, if fast forward or reverse is selected a pronounced CLICK can be heard and then a second CLICK. Nothing happens with the motor as the fuse is blown.

Also, with the fuse blown and I select PLAY the heads engage briefly and then retract. They will engage as often as I like with the PLAY button depressed.

Again virtually everything appears to work properly except engaging the motor blows the one 250mA fuse.

As you know I tested the original motor with a 9v battery (away from the 9000) and it works. So now I have two good motors both with their transistor boards in place, but the fuse blows attempting to use either one.

It does appear that we have narrowed the problem area. I hope that this new information helps.

Jeff

Jeff:

Again...I refer you back to post 154952 of this thread.

Derek

Derek:

This is the second time that you have referred me to a previous post. While I very much appreciate your expertise, I would be ever so much more inclined to follow your directions if you explained WHY I need to do this.

1) Does the fuse blow when you power up and hit play with the motor REMOVED. Why is this important? The fuse blows repeatedly with the replacement motor in place. It also blows when reverse, fast forward, or play is selected. In short, the fuse blows any time the motor is engaged. This is EXACTLY what happened with the original motor.

2) If it does not what is the voltage reading at the output of the fuse I am only an enthusiast, an ordinary person who loves B&O products…. one lacking in ANY B&O repair facility for hundreds of kilometers. (The only one in Vancouver only answers his phone when he feels like it…. and that isn’t often.) The voltage output at the fuse? How do I test this when the fuse blows in seconds?

How are you testing the motor? I replaced the 250mA fuse and pressed STOP. The motor ran briefly…. I’d say 5mm or so and the fuse blew. I put in yet another $5.50 fuse (yes things are expensive here on Vancouver Island) and tried REVERSE, which caused the replacement motor to run briefly again and the fuse blew.

Are bypassing the transistor when you are powering through the battery? I am not powering the motor through a battery. However, if you want me to bypass the transistor first tell me why, and second tell me HOW!

Did you test the Bill Rapp motor also with battery? No, however it powers up within the Beocord 9000 until the fuse blows. Does it power up? The answer is yes.

I used the 9v battery to power up the original motor (YOUR SUGGESTION), now out of the Beocord 9000 to see if it worked. It does. With the 9v battery attached the original motor runs beautifully and with none of the growling I associated with it before the Beocord 9000 stopped playing cassettes.

Derek, I don’t know what your background is, but I am just a regular guy, a middle aged retailer with a degree in history who happens to LOVE music….. and B&O products in particular.  

BeoWorld has enabled me to repair my exasperating but cosmetically flawless Beogram 4002 through countless adjustments. (I think I hold the record for the number of adjustments required to play a single record.)  More recently getting my Beogram 4004, my most dependable turntable to track properly and my Beogram CDX to once again play CD’s. All are now performing splendidly.

Help with my Beogram 4000 was less successful, but in the end, all that was wrong was the wrong fuse…. Yes a 250mA fuse, incorrectly used….. and all it took was a trip back to Denmark, where Martin put all things right.

I am a guy that can talk to you for hours (reasonably intelligently) about Tsar Nicholas II of Russia, Frederick the Great of Prussia, or Alexander of Macedonia…. but with electronics, I need guidance with clear directions. At the very best I am an amateur forced to deal in a most unfamiliar world.

As such, I thank you for your patience with me.

Jeff

Think this through...

You have a motor driver which supplies power, a fuse, a few components, a transistor and a motor.

Start from motor driver and work your way through the chain.

We first test for presence of power which you've done (fuse blows) Fuse wont' blow if there is no power.

We should test for presence of correct power, which you haven't done. Measure the output. But you need to remove the load because if there's a short, your voltage readings will be incorrect; As you have observed, you can't measure the output if the fuse blows. Remove all unknowns that can cause fuse to blow ie everything after the fuse. REMOVE MOTOR.

 1) Old motors can have bad brushes, which causes shorts thus blown fuse. I had you test the motor to eliminate bad motor scenario. Of course when you have a bad motor, the circuit will short every time regardless of whether you have 250 mA or 800 mA fuse.

You still haven't tested the motor that you are using in the deck so we still can not eliminate the possibility of a bad motor. Note you can have good motor with shorted transistor thus that's another thing to examine. All you've confirmed is that the motor you thought was bad is good. But that's no longer in the system and not really relevant as its sitting on your desk on in the deck.

2) You should remove the motor and measure the voltage output at the fuse because you want to know if the fuse will blow without a load. If it blows then it means something is shorted between the motor and the motor driver. You should then look at the component path beginning from the output of the fuse through to the motor. The fuse will not blow if the circuit is open. If it does, then its not the motor and transistor, its something in between.

3) How do you measure? One probe on the the fuse and one probe to ground.

In general the procedure is get as close to the fuse as possible eliminating variables (motor, transistor etc..) until you are able to power up without the fuse blowing. Then start  adding back until it shorts out again. The part that you add that leads to the short is the part that needs to be replaced.

We can't really do more until you've looked at these areas.