[Mark-sf]

You should realize with a cartridge likely over 30yrs old and and obvious suspension issue and unknown diamond wear, that you are likely doing damage to your records which may in total be more valuable.

[Mark-sf]

I’m afraid it does. You are not likely to be able to get it rebuilt, but Soundsmith sells an SMMC4 for $230 as a replacement. They are reputable.

[Mark-sf]

I would first check to make sure that at rest, cued up, the stylus is centered. If it is, then the shutter is misadjusted. You may see evidence of that when the arm is cued down, in that the tonearm moves a bit laterally instead of dropping straight down.  When the belt is off, and the arm is cued down on a record, it should drop straight and then not move for 2-3 revolutions of the record.

[Mark-sf]

You mention shorting transistor 6. The one directly controlling the solenoid is IC4. What you need to check is whether TR9 gets .7V when you press the down arrow. Most 400x turntables at this point need the electrolytic caps replaced at this point and their are kits available to do that online such as beoparts.com.

 

 

[Mark-sf]

You’re welcome. Enjoy!

[Mark-sf]

These cartridges are 50 years old and there is little doubt that the suspensions are shot even if the diamonds are fine. These diamonds, especially the 6000 are so small that unless you have a stereo microscope, you would not get an accurate picture on wear. You can confirm that the channel(s) is out due to they coils in the cartridge my measuring the hot and gnd of each channel at the cable with the arm cued down. If it measures significantly higher than 1000 ohms the cartridge is not salvageable.

[Mark-sf]

If the base of 8IC1 is getting .7V when the arm is set down, then then it should be effectively “grounding” the end of the relay which is what you did manually. If that is not happening it is bad.

[Mark-sf]

Since it works fine on 33, I would check a few things about the 45 speed.

1. Do you have the problem with a 45 LP as well as a 7”?

2. There is a speed adjustment dial at the on the upper edge of the control square as well as a trimmer on the circuit board that you should try cleaning or at least moving back and forth several times.

3. I would check that the platter is not touching anywhere and moves freely up and down/l-r when a record is on.

4. The single likely culprit is the speed selector relay. Since 45 is rarely used, the contacts have been known to oxidize and the best approach is to replace the relay.

[Mark-sf]

It’s actually Pin 1 that is biasing 8IC1 to turn on and close the relay. You are getting the correct input voltage so I would look at the trimmer 8R2, 100mf cap, 8C1 and diode 8D2.

• This reply was modified 4 months, 2 weeks ago by Mark-sf.

[Mark-sf]

I would check the voltages on the muting relay board. You should have 21V DC on P1 of the P8 Connector and .7V when the tonearm drops to open the muting relay. You also might try cleaning and adjusting the muting relay delay trimmer, 8R2.

• This reply was modified 4 months, 2 weeks ago by Mark-sf.

[Mark-sf]

Do you hear the click of the muting relay after the arm sets down? Have you tried using the cartridge from your 2402?

[Mark-sf]

It depends on where the break is and your adeptness. You are correct that they are enabled wires that are typically used in winding transformers. If the break is past the point where the wires exit the back, then they can be carefully spliced after removing the enamel and soldering. If it is within the tonearm, you would have to remove that cartridge connector which is glued in. The wires are solder to a small PC board attached to the connector. It requires a needle-tipped iron and a steady hand with magnifier.

[Mark-sf]

You should be able to as that transformer was used on may models during that period. Since failures are rare, what type was it? If it was the wrong voltage selected (over-voltage) I would replace the power supply components as well. The caps in any case.

[Mark-sf]

Welcome to the forum! I would start checking the power supply voltages per the service manual. Given the units age, it may need new electrolytic capacitors or has a bad regulator.

[Mark-sf]

Check that the tonearm measures 53mm above the top of the surface to the top of the arm. Also check with the carriage moved to the center and the platter off that there is 2.5-3mm of between the top of the subchassis and top of the turntable surface all the way around.

[Mark-sf]

It looks like a normal return. The electronics cannot fail in a manner that would only speed up the return.

[Mark-sf]

Those adjustments are spelled out in Sections 5.1 and 5.3 of the service manual.

[Mark-sf]

It would be best that you post a sound clip of the noise as it’s too generic to assist. I would suggest to record with the tonearm lowered next to the record and also in a a silent groove to compare.

[Mark-sf]

The arm is slipped over a rod attached to the sub chassis and its held be a washer and circlip.

[Mark-sf]

Nothing is wrong with it as that’s the way it was designed. There were no 12” 45’s in its time.

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