[Mark-sf]

There are small knurled knobs under the black trim aligned with the speed indicators.

[Mark-sf]

From your picture it is missing the veneer. Quite frankly I was never a fan of that motor but you have nothing to loose in trying to relubricate it. Cannot comment on how long it will last. I would also have the stylus checked for wear as you don’t want to be damaging your records.

[Mark-sf]

To answer that we are going to need a bit more information.

1. Does the noise vary with volume and turn off when muted?
2. Putting your ear to each driver (tweeter and woofer), do you hear the noise only from one or both? Note that the tone will be different.

 

[Mark-sf]

IC1 is a voltage regulator and the operation is the same in that it is being turned off by the SO switch grounding the anode of D5. I would confirm that is occurring.

[Mark-sf]

If the 1200 has the phono preamp then you would connect to an AUX/CD/Tape input on your Marantz. If not you go into Phono making sure MM is selected versus MC if your Marantz has this. Either the stylus or its suspension may have worn out which is not surprising after 40+ years. Finding a replacement will be costly or lucky.

[Mark-sf]

Welcome to the forum. First, I would check that your cartridge stylus force is adjusted properly. It should be 2 grams.  You will need a stylus force gauge as I don’t believe there were calibrated markings. If this does not solve your problem, I would check whether yours as the phono card plugged into the bottom. If it does then this could be at fault. Which inputs are you using on your Marantz?

[Mark-sf]

No, a TR is not an IC. You will need to trace the circuit but you have the SO switch as a reference. Just follow its high side.

[Mark-sf]

Does the turntable motor keep spinning as well as the lamps stay lit? If so, you still have an active 22.8v rail and OTR1 is not turning off. Is the anode of 1D1 grounded when this occurs?

[Mark-sf]

I was referring to the switch marked “SO” that is on the Arm Transport PC board. This keeps the TT off when the arm has returned to rest. Sometimes the optical bar can be misadjusted in its engagement of the switch or it can be dirty as its contacts are exposed. As to D1, I am referring to the diode that is between a 2.2K resistor and the base of TR1. I highly doubt it changed for your type.

[Mark-sf]

I’m afraid you are not going to find a new one. Your best bet would be to find a used non-working 3404 with a reasonably clean cover, that you could then part out to recover some or all of your cost.

[Mark-sf]

Sorry, I don’t have experience with the Beolink products that came later to answer.

[Mark-sf]

For a start all of the electrolytics should be replaced, Thes are the cylindrical (horizontal or vertical ones) paying attention to their polarity. I would also clean and check the alignment of the switch that is activated by the optical rail when it returns to rest. This should be grounding the base of TR1 via diode D1.

[Mark-sf]

If it has never been repaired it is overdue to have its electrolytic capacitors replaced. Once this is done and the voltages confirmed your problems would likely be solved. This can be done by a competent technician even without B&O experience.

[Mark-sf]

This could be multiple issues including the servo belt, threaded rod alignment and cleaning/lubrication, loose or cracked pulley, etc. I would attack the mechanicals first before the electronics based upon an issue in only one direction.

[Mark-sf]

Have you performed a re-cap of the electrolytics on the board? The symptom points to it needing that.

[Mark-sf]

You can find the service manual based upon your 5500 Type at beomanuals.com or if you become a Silver member of this site. The procedure is documented there.

[Mark-sf]

I would not suspect the motor in this case based on your symptoms and what you have done to date. You can confirm if you have a 45rpm LP which should make the wow significantly worse if it’s a motor issue. I instead would check the adjustment of the tonearm optical shutter and ensure it is within the i.5 to 2.5 initial rotations and how it behaves toward the end of the record. Since the curve is tighter, if it is not correcting fast enough it can sound like a speed variation.

[Mark-sf]

“Fast” backwards,>>, is the same as Stop so I am still not sure what you are describing. How is the speed compared to moving forward between Play and Stop as well as < and >?

[Mark-sf]

I’m not sure I understand your symptoms. You say going to stop works fine but fast backwards doesn’t. Those functions use the same circuit except for how they are activated. Are you saying that the arm returns fine at the end of record but simply raises and doesn’t when you press Stop?

[Mark-sf]

Great to hear! Keep ’em spinning.

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