[Mark-sf]

That’s a non-intrusive  way to execute it. I couldn’t see from you pictures where the other wires went.

[Mark-sf]

Very clever idea; however, I would add a diode in series to protect the processor as its not a good idea to drive 5V into its outputs when you use the manual keys.

[Mark-sf]

Actually what you are observing is the 8002 going into protection mode and locking out all functions. This can be caused by several faults:

1. Failed Carriage Tachometer / Optical Encoder (Most Common)

The tangential carriage drive spindle relies on an optical tachometer (an IR LED and dual photodiode assembly reading a slotted disk) to tell the CPU that the carriage is actively turning.

 The Failure: The original IR emitter LED (OPE1 on the board) frequently goes open-circuit over time.

 The Result: The carriage starts moving, but because the CPU receives zero “slide tacho” pulses from the sensor, it assumes the transport mechanism is jammed and cuts power to the carriage motor to protect it, freezing control inputs.

 Fix: Replacing the IR emitter diode (a common modern replacement is the Optek OP240 or equivalent) on the spindle encoder PCB.

2. Servo Belt Slippage or Mechanical Binding

If the electronic sensor is fine, the carriage may simply not be moving smoothly.

 The Failure: Old grease on the threaded lead screw and guide rails hardens, or the small rubber servo drive belt has stretched/perished.

 The Result: The motor turns or slips on the belt, the carriage stalls mid-track, and the missing optical pulses trigger the same 2-second safety timeout.

 Fix: Clean off old oxidized grease from the threaded shaft with isopropyl alcohol, re-lubricate with fine synthetic oil/grease, and replace the carriage servo belt with a fresh, correctly sized belt.

3. LDR / Aperture Sensor Drift in the Control Panel

The manual transport buttons (⁠<<⁠ / ⁠>>⁠) work by moving a mechanical light aperture between a small bulb and photoresistors (LDRs).

 The Failure: If the photoresistors age or the calibration adjustment screws in the control assembly drift, the resting voltage fed to the control op-amp rises above the threshold (resting target is ~0.61V).

 The Result: The CPU gets confused by the unexpected voltage rise during automated movement and halts the carriage drive.

 Fix: Re-calibrating the aperture adjustment screws on the control board according to the Beogram 8002 service manual procedures.

4. CPU Board Solder Joints & Power Supply Capacitors

 The Failure: Cold solder joints around the microprocessor socket, edge connectors, or dried-out electrolytic capacitors on the main board causing supply voltage ripple.

 Fix: Inspecting the main board for cracked solder joints and performing a standard capacitor refresh if the deck is still running on original 1980s components.

• This reply was modified 2 weeks, 1 day ago by Mark-sf.

[Mark-sf]

First, was the plater on when you tried this? If not, try it with? If that does not work, try pressing Stop instead of >>- what happens?

[Mark-sf]

I’m glad to see you’ve got it working. our comment about every 5 revolutions is incorrect, According to B&O’s calibration procedure, the servo motor shutter should be adjusted to cause the servo motor to run every 2-3 revolutions.

The first picture is definitely a damaged diamond and will do damage to your records which is why you should be diagnosing and testing with a record you don’t care about.

• This reply was modified 1 month, 1 week ago by Mark-sf.

[Mark-sf]

All of that type of information that is available is in the service manual. The schematic will show how it works, If you do not understand the operation from it then let us know the specific problem you are having.

[Mark-sf]

The speciations are at the end is the service manual.

[Mark-sf]

Yes you should perform that adjustment and no you do not need a test record.

[Mark-sf]

The click you are hearing is the muting relay and independent of the solenoid.

[Mark-sf]

The extra pins in the DIN connector are for a datalink connection allowing the remote control from the receiver to control the turntable. Those pins can be unscrewed from the Beogram ouput dim. If there are no holes for them, likely the cable has been changed and perhaps grounded incorrectly. Pin 2 is the audio ground and should have continuity to the DIN connector shield and the chassis of the 8002.

[Mark-sf]

I gave those to you already.

[Mark-sf]

TK wrote:

Platters also come up for sale quite frequently in various marketplaces, ranging from USD $50 to $100.  In the mean time, you might consider milling two solid discs with a diameter of 10cm each.  Place a layer of rubber on the bottom one for a bit of grip.  Place the bottom disc on the spindle with the rubber facing up, next the record, last the top disc as a weight to hold the record in place and level to the bottom disc surface.  You might need to make the top disc a bit heavier to provide additional stability.  I haven’t tried this myself, but I feel like it would work fine, provided it is balanced properly, and can compensate for the 1.5g of downward pressure provided by the tone arm.

This is really not a good idea. First, the record need full support underneath which is 300mm. Secondly, for this motor design the correct weight is very important as there is a tight servo loop and additional weight can cause undesirable rotational inertia. Finally, the MMC1-4 cartridges tracked at 1.0 to 1.2 grams.

 

[Mark-sf]

The platter diameter is 300mm and the height is 24 mm; however, it was not a solid piece of aluminum as it was cast with the underside hollowed out. I believe the weight was around 1.5kg but was never published. A solid piece would be too heavy at about 4.6kg. This would require you to remove about 16.mm of material except for a 1-2mm outside edge. For this motor design it’s essential for the platter to be light weight as the servo system with its ~200mm rotor would be impaired by the higher inertia of a typical direct drive platter. You would also need to stencil the black ribs. The black rotor that supported the turntable platter was part of the motor. Do you have that?

• This reply was modified 1 month, 2 weeks ago by Mark-sf.
• This reply was modified 1 month, 2 weeks ago by Mark-sf.

[Mark-sf]

There is no possibility to pick a single song.

[Mark-sf]

I have not seen this type of malfunction and I would suspect it may be related to how you reassembled the motor. This is because it generates the frequency that ultimately governs the speed. Unfortunately that can’t be confirmed without an oscilloscope or a frequency meter. You can get a multimeter that measures frequency for under $50 (as well as capacitance), so I suggest its a good investment if your current one is inadequate.

[Mark-sf]

First, I would check all of the voltages around the 1IC3 and the 8.5V at P1 Pin 3. While you’ve replaced the electrolytics, sometimes the tantalums can also fail. If you have a scope or frequency meter you can check the feedback frequency of P1-1 which should be 125Hz for 33 and 167 for 45. Now all of this pertains to the DC gold motor.

If you have the older AC silver motor then the frequencies are 42.3 and 57.3 respectively at 5V AC. You should have also changed the 4000mf motor cap. You should also get 11.4VDC on its transistor side.

[Mark-sf]

Yes there is though not inexpensive at https://www.designedav.com/connect-bo-turntable-to-modern-systems. You can make one yourself with 7-Pin DIN male and female connectors where the L/R signal uses male RCA connectors to connect to an external phono preamp and pins 6 & 7 are directly connected with a wire between bypassing the preamp.

[Mark-sf]

B&O does not produce an external phono preamp for its turntables, but there are many out there depending on your country. Here in the US but available internationally, a particular fine one is the Schiit Mani.  As to repair ability between the 7000, 6500, and 5500, they are equivalent as they share many of the same parts. It was the 5000, I would not bother with.

[Mark-sf]

The Beogram 6500 or 7000 would be your best choice since it came with the phono preamp built in. Otherwise, it is the same as the 5500, which would require an outboard preamp. I would avoid the 5000 which is older.

[Mark-sf]

The answer is unchanged. Follow the procedure in the linked manual or video.

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