[Gabe]

Hi Mark,  Primarily, I’d like to make sure my original Beogram 2400 & MMC4000 are in the best shape possible, and the Elliptical Stylus at 1.0 to 1.2 grams set to best preserve my vinyl. In the past couple weeks I’ve now restored three 2400’s; mine and the 2 eBay units I bought for parts, but was able to get all 3 reliably fully functional. (Well, the 3rd has a stubborn to engage Pause and Stop that may be due to a missing or stuck Dog Catch under the Cog Wheel. Pardon my Danish, I mean Release, Switch Arm, Hammer, Cam, Release. Anyway, I’ve really had a lot of fun!  And hearing my soft-sleeve-stored vinyl for the first time in 35 years brought tears to my eyes. (35 years? Yea, graduated – work – marriage – kids – now retired.) But 35 years!!!? Well our home came with two built in theater surround systems (no phono just CD/DVD), and I was lazy. Now also breaking out my Bob Carver Cinema Grand and Yamaha NS-1000M Speakers, that I may do a Crossover CapBank re-build.

So, I love the elegance, simplicity, AND performance of the 2400. I may keep looking for re-build projects AND cartridges. MMC’s that do not meet snuff will go to the experts with tiny fingers for re-build. And so, I think I would like to invest in a Strobe, Test Record, and Scope. I found:

Strobe & Light $30.29

Stylus Force Gauge $12.95

Sharp Track-ability Test Record $19.23  (B&O Test Record 3621004 anyone?)

RCA to BNC Adaptors $6.99

Handheld 2 Chanel Oscilloscope $89.99, Or BenchTop 2 Chanel Storage O-Scope $154.

So, $159.45 to $223.46 for all the new equipment I think I’ll need. About the same as an eBay re-build project.

Here are the photos of what i’ve found…  Cheers, Gabe

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[Gabe]

Mark-sf,  Thanks, your instructions were spot on. I would have responded sooner but I was waiting for new drive belts and a 2400 Service Manual to arrive from eBay, so I could drive the Platter properly, and possibly see a diagram of what you described. The 3 Hight Adjustment Screws go to Cleats that deform the 3 Leaf Springs, and have a prevailing torque so they will remain where set. I turned all 3 counterclockwise a half turn and tested, and then did an additional half turn each. Platter now floats perfectly, just as my original 2400.  (I will bubble level it once the turntable is in its final position.)

The (thin) Service Manual is kind of funny. Written by B&O’rs for B&O’rs, if you do not already know the turntable well, there is a lot of assumed information simply not discussed. For example, setting the Stylus-Force in the section called Pickup Arm Balance. There is no way to teeter-tot the Tone Arm about -0- with the Stylus and Weight installed while the Tone Arm Lift mechanism is in the raised position. It is best to do this adjustment (with a scale if you have one) with the Lift descended, and that is by playing a record, and unplugging the power. Now you have total free control of the Tone Arm, and can play with balancing it, either at -0- force (a level teeter-tot) or against a Gram Scale equal to what is set on the Tone Arm Scale.

Of course there is a lot of priceless information too. For example setting pots R4 & R5 for 33-1/3 & 45 rpm is accessible from the top after lifting the thin black plastic disk. Now I just need a Stroboscope Disk and Lamp. My plan WAS to use a piece of white tape on a record and count revolutions against a stop watch.

Wish List after reading the Beogram 2400 Service Manual:

Stroboscope Disk & Lamp

<b>Test Record 3621004</b>  & 2 Chanel Oscilloscope (To test and adjust the Anti-Skating.)

Instruction Diagram  3535056  (This might just be the Owners Guide pamphlet.)

Anyone ever seen “Test Record 3621004” and where to buy one? 

Test question: Why wouldn’t a copy on tape or CD work?  🤣

Thanks Mark-sf, and anyone else that might have a lead on my wish list.

Cheers, Gabe

[Gabe]

Slight update to my post: Warning – Spring loaded Cover  and Back Panel.

In retrospect, it is best to remove the back panel with the Cover UP and OPEN. This puts the Torsion Spring in a more relaxed state. With the cover and back panel removed by removing the 3 cleats (NOT the Hinge Clamps) remove the platter and lock the floating turntable by turning the 3 large slotted screws counterclockwise with a (US) Quarter or similar. Prepare some blocks to rest the turntable on. I discovered two times 4 DVD boxes makes a good support. Carful of the tone arm, you may wish to lift out and remove the lead weight first. Now flipped over, you can remove the two captive Philips screws and the bottom cover.

[Gabe]

Hi, I just refurbished two 2400’s back to back. See my response to “2400 Muting Switch” earlier today for a description and photos. Yes a new belt too.

Gabe

[Gabe]

The Floating Suspension:

Remove the Platter and you will see 3 big slotted head screws. A quarter fits well.

Turn and raise the 3 screws fully counterclockwise to lock the turntable for shipping or moving with no bounce.

Turn the 3 screws fully clockwise to release the turntable to rest on its 3 leaf spring suspension.

Gently place you hand on the wheel and push down slightly, and you can feel the soft suspension.

Now place the Platter on the wheel, and the turntable should be “sprung” to just float. This is excellent.

I have an odd situation I cannot figure out. My 2400 that I bought in 1976 floats perfectly. But my eBay 2400 I just got and restored, requires that I place TWO platters on it to get it to “float”. The 2400’s are exactly the same, but the eBay one seems to have “stiffer” springs. Any ideas to fix this? Adjust or soften?  Thanks,

Gabe

[Gabe]

Hi, I just did this on a B&O I got off eBay and fixed up a couple days ago.

Play a not critical record and have the tone arm run in the middle.

While playing, push nothing on the Control Panel and Pull The Plug to cut power.

While holding the tone arm, slide the clear plastic force indicator to 1.0 grams.

Set the B&O Gram Balance (Kit came with my MMC4000 cartridge in 1976) on the center of the record and place the stylus in the groove at 1.0 grams. (Saw a MMC4000 cartridge kit box on eBay about $90, no cartridge of course.)

Look to see if the balance teeters level. If not, use a small screwdriver to move the Lead Weight in the Tone Arm in and out. There is a small hole in the back of the tone arm to reach the slotted set screw in the weight. I think there is a small hole in the dust cover too, to reach through and access the set screw. While holding the tone arm protecting the cartridge, you can wiggle the weight loose by grabbing the edges of the small rectangular aluminum plate. Look at the set screw and see how it works. You can adjust it and press the weight back into the tone arm as well.

When your Tone Arm indicator is set to 1.0, and the Balance teeters at 1.0, you are golden.

Now set the sliding Tone Arm Scale to around 1.2 or whatever your cartridge and records need.

Remove everything placed on the record surface or elsewhere, and plug your B&O back into the power outlet.

Gabe

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[Gabe]

Ref: Shunt (mute) Switch. Yes, your description; cartridge ok, but moves with changing RCA plugs, indicates the moving shunt.

You have to close the cover and turn your player upside down, and remove the 3 base clips & screws (NOT the 3 hinge spring screws!). And then about 2 inches in from the front on the bottom there are two deep hole hidden “captive” Phillips screws (you may hear plastic clicks as you loosen them). Then remove the black plastic bottom, called a plinth.

Hi, I recently took my B&O 2400 out of 35 year storage, and discovered issues with the tone arm lift, and then the control panel fell into the body. OMG! While searching for clues on various forums, I found this forum too. I was able to fix all my problems, and also fixed an eBay junker I bought for parts to new-like as well. Both required basically the same work.

I fixed the Tone Arm lifts by using fancy fine synthetic oil on the Brass Plunger Brass Housing interface. Soak a drop – gently work it – add a drop work it some more, etc.

Both Control Housing Assemblies were a complicated clean up and re-build, with added custom structure to support broken parts. They now work excellent.

While researching and fixing, I  encountered two B&O 2400 Shunt Switch designs. Both are activated by the long arm that activates the tone arm lift and decent. My two B&Os have the same design, I believe the more recent of the two. The other I saw in photos of a guy who was having lift issues. Both designs have a fixed fiberboard with terminals for tone arm SUPER fine wiring and RCA phono cable end soldering.  A vertical fiberboard anchored to the sliding arm has shorting-knives in it that enter tabs on the fixed board. If you have problems, I suspect debris in the tab slots and shorting-knives (easily cleaned), or far worse, damage to the SUPER fine wires coming from the tone arm, or their delicate solder connections. You have to have the skill to count angels on a pin head to be able to fix those SUPER fine wires. Be VERY cautious moving around those fine wires.

So, hopefully, all you need to do is clean the shunt tabs and knives. AND not touch those fine wires. If that fails, perhaps it’s faulty tone arm wiring. While you have the unit open, DEFINITELY lube the brass lift plunger, and remove the four screws holding the Control Panel Housing, One By One, and add a washer under the heads of the screws. You will certainly see some cracking in the clear plastic cover  around the screws. Some lube inside would be great too.

Good luck, let us know how it works out – the cause of the missing channel… how were those other parts I mentioned?

Gabe

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