have you tried measuring motor voltage at its own terminals when pressing volume? Also, do you remember what I said abot these motors a few posts ago? Maybe unlikely with yours but if you are getting a decent voltage at the terminals then you should not jump to completely writing the motor off!

Yikes, you mean your posting back on page 3 where you mentioned taking the motor assembly completely apart and re-lubing?  Isn't TP20 and TP21 the same point of the motor terminals you are referring to? 

So you have attached your meter leads directly to the motor terminals and measured more than a few volts when operating the volume keys?

If so, your motor is obviously knackered or stuck. Could be that the belt has slipped off and squeezing between pulley and gearbox housing? remove belt and try again...
If still no life then the motor can be pulled apart quite easily but a great deal of care must be taken with the motor brushes...

I have seen two of these that were completely siezed and one that was very nearly siezed, so if I see another 6000 I would make it part of the routine now...

Here is a picture of the volume motor. On the left picture you can see TP20 and TP21 marked just under the board connector.  TP20 is the purple/white wire and TP21 is the solid purple wire.  The picture on the right shows those TP wires connecting to the motor.  It was easiest for me to attach the scope probes to the exposed connector terminals so I did that.  I attached the scope grounds to the metal tube around the motor.

When the Beomaster is on and the preset is at zero or if the zero volume keypad button is pressed, the voltage at TP20 is 1.45V and TP21 is 14.13V.  When I am pressing the down volume control button TP20 is 4.3V and TP21 is 10.4V.  Pressing the up volume control button pretty much is the reverse - TP20 is 10.5V and TP21 is 4.1V.

What about the effect of pressing the up and down volume buttons on the tuner? That is pretty odd isn't it. Is it some sort of electrical noise by the motor trying to work that is affecting the tuning? 

Why would you assume the metal case around the motor is grounded? I don't think it is! Get your meter and directly connect it to the motor terminals. Use jump wires or solder some wires directly or whatever... How do you know the voltage is getting to the motor if you haven't tested at the terminals?

Now if the motor isn't moving it is unlikely to be producing interference in your radio! That indicates a bad earth or something equally odd (loose plug? bit of solder dropped on the motor control board)  but lets get the motor running first.

I disconnected the belt from the pulley to see if the motor would run and it still doesn't do anything.

disconnect the wires and run the motor off an external supply?

You are right, I measured the metal case to ground and it isn't connected to ground.  When I put a voltmeter across the two motor terminals I don't get any reading when operating the volume control.  I also tried putting my scope probe across the terminals.  When I do that I get the old problem of the processor going into an unknown state ("P" displayed at start up). I have my scope probe set to X10 but it still affects that voltage somehow.  

I can try that.  What should I apply across the motor, 10 volts DC?

These motors are quite sensitve, so you should get something with a couple of volts, but the motor should also be quite strong at the stated 6v from the manual. I think when you use the direct entry it may be 12v but I can not remember. Best not to push the motor especially if it is jammed as it could cause irriversable damage! Limit the current or at the very least keep an eye as you raise the voltage!

Oh and remove the belt so you don't have to worry about the dial hitting extremities!

just re-read your post and realised you have probably already determined that the motor is ok, just by the fact you are measuring no voltage across the terminals! So, check each terminal in relation to main system ground in turn hitting both up and down, this might give you an idea if both terminals or just one is involved. Then go back to the board and move backwards to the driver IC.

I assume you have checked all plugs and sockets..? and also drys on the boards?

I tried an external DC supply.  The belt was detached from the pulley. I also disconnected the P17 plug to the 06 Module. I started with the current and DC voltage at zero and slowly increased it to almost 7 volts.  The motor didn't ever make a sound.  I powered down, reversed the polarity and tried again but got the same result.

It looks like my options are to repair the motor.  I am not sure if I will tackle that today though.

ok I will retract my last post edit lol! Does the motor pull any current?

I retested applying DC voltage with an external supply and the high side through my ammeter.  I am not getting any measurable current. 

Well that is the last thing I would have expected tbh! Fuse ok in your meter? try measuring the resistance, turn the shaft while monitoring... although you might struggle with gear reduction so maybe take the whole thing out.

I was figuring I was heading down the path of having to take it out.  It will be a few days until I can get back to it though.

In the meantime I aquired another Beogram CDX unit that was being sold for repair/parts. Surprisingly, this CDX has perfect lid hinges. The other CDX I have was working but something involving the lid detection and other mechanical detections drifted out of alignment so the timing to center and read a CD is no longer functioning. I'll wait until I get time to actually try out the new CDX before I decide but I will need decide if I will just try to repair the new unit or use parts in my first one.

(plus I have three amplifiers that I need to recap)

-Sonavor

Arggg!  I was so close to getting a nice parts BM6000 off Ebay for $75. The seller had told me the unit was semi-working and had burned out segments of the display.  I figured it was a good candidate to get an extra set of parts for mine. Some buyer with a super high transaction count swooped in and took it away. Oh well, I will wait for the next one. I thought I had a good chance though. The last couple of BM6000's that were advertised as having no problems sold for between $120 and $227. Maybe the buyer was in the same boat as me and needed the parts.