[auric]

I have added a PC board pin type battery holder for the CR240 for my BC9500.

Something like this: https://www.digikey.com/en/products/detail/mpd-(memory-protection-devices)/BS-2450/2439475?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=PMax%20Shopping_Product_Low%20ROAS%20Categories&utm_term=&utm_content=&utm_id=go_cmp-20243063506_adg-_ad-__dev-c_ext-_prd-2439475_sig-Cj0KCQiAwvKtBhDrARIsAJj-kTgQ1PRRQ-jG3MJNQ-8cw_m-ioEObZWFzUCJiz59GgpVyc1ockdgeakaAu5OEALw_wcB&gad_source=4&gclid=Cj0KCQiAwvKtBhDrARIsAJj-kTgQ1PRRQ-jG3MJNQ-8cw_m-ioEObZWFzUCJiz59GgpVyc1ockdgeakaAu5OEALw_wcB

Then it allows you to use normal button cells without desoldering in the future.

Be very careful when desoldering lithium batteries. Please wear safety glasses. Any leaking residue can cause a nasty “bang,” with lots of smoke if the it gets on the soldering iron tip.

 

 

[auric]

Christian:

They are available here:

https://www.electronicparts-outlet.com/en/integrated-circuits/4688-mullard-fch131-dual-4-input-nand-gate-with-rc-dip14.html

https://www.electronicparts-outlet.com/en/module/iqitsearch/searchiqit?s=FCH+111

FCH131 is a 4 input Nand Gate. Can you use a 7420?

FCH111 is a 8 input Nand Gate. Can you use a 4068?

Those are much cheaper if they work. I didn’t check the pinouts and operating parameters.

 

Derek

 

 

 

[auric]

Hi Guy:

I would recommend replacing all of the belts while you have the unit open.

I’m finding that the plastic parts on the 1990s B&O are becoming very brittle over time. The plastic is literally crumbling apart and nearly impossible to repair with super glue or epoxy. The plastic parts that receive the threaded screws are particularly suspect.  I live in North America and I’m not sure if it is a climate thing.

It’s a risk every time you open the thing.

Get it all fixed and done with and hopefully it will be good for another 20 years.

Derek

 

[auric]

Thanks Guy.

So I stand corrected! I’ve never seen a 9300 here in the US with a radial mech. Looking into this further I found a photo in the archived section of the Beoworld:

https://archivedforum.beoworld.org/cfs-filesystemfile.ashx/__key/CommunityServer.Components.PostAttachments/00.00.16.60.51/99K-Done-_2D00_-Interior1.JPG

The CD interface board on the BC9300 is very different from the CD interface board of the BC9500.

So I wonder if the radial mechanism on the BC9300 is interchangeable with that of the BC9500. (The CDM4 lasers are interchangeable)

But I suspect the interface is a bit different on the full CD mechs?

 

 

 

 

[auric]

When I refer to the controller, I mean the long vertical board along the right side of the BC2300 right behind the right black acrylic cover.

There are two components, the CD mech which has a circuit board attached to the back, and the interface (“controller”) a separate circuit board. CD mech plugs into the interface and the interface plugs into the rest of the BC2300.

[auric]

Hi Guy:

Did the BC2300 linear version ever have problems playing CDRs even when new?  My BC4000 was purchase used with a dead laser and so I have no reference to what it “should have been” like.

I ended up swapping the laser with a new one to get it working. As I mentioned it plays all pressed CDs fine, just very picky with CDRs which I’m not too crazy about but at least its working.

I did swap the surface mount capacitors on controller card mounted on the back of the mech first. It didn’t do anything. I ended up going through 2 different laser pickups. The first one I bought on ebay didn’t work. I think there are a few different versions and you need to find the right one. The second laser I bought from a local Juke Box repair company. That one they provided worked.

They also gave me a tested working controller board, the one that I replaced the capacitors on. That didn’t work with the BC4000. We suspect there maybe different firmware on there. Anyhow I went back to the original controller with the new laser and it plays.

Derek

 

 

[auric]

Madskp, I’m assuming you are asking if the CDM4 (radial) and CDM12 are interchangeable?

If so, the answer is not directly. B&O at one point offered upgrade kits, for example for the BC2300, and BC2500. It came with a new decoder board and CDM12 mech, new mounting hardware and front fascia.

So each mech requires its unique respective controller and decoder.

Without the kit, I suppose if you had a BC2300 radial version, and a BC2300 linear version you probably have enough parts to get swap from one to the other.

The BC9300 never came with a radial laser. Not sure if you can go backwards here.. the internals and layout are different from its predecessor, the 9500.

 

[auric]

Hi Guy:

What is your experience with the Philips CDM12 linear pickups?

I used to have Beocenter 2500 (Radial Pickup) and a Beocenter 4000 (Linear Pickup).

I found that the radial pickups will play anything… pressed CDs as well as CDRs with no problems.

The linear lasers seem to be more picky. My BC 4000 plays pressed CDs fine. It doesn’t do well on CDRs even after laser change. It seldom plays CDRs perfectly from beginning to end.  Some CDRs are unreadable others will skip near the outer tracks.

Derek

Derek

 

 

 

[auric]

Hi Zuegers07:

The clicking sound is mechanical. It doesn’t come through the speakers. It’s from the mechanism.

The sound only happens when the CD is spinning up and reading the TOC. Once it starts playing there is no clicking sound. It is as if when the laser is being recalled to the center of the disc to read the TOC, the sled motor continues to run even though laser pickup has reached the start position and unable to run further. It’s also intermittent. Once every few times and more often form a cold start.

 

Derek

[auric]

Martin:

Thanks for the tip.

Cleaned the switch. It didn’t fix the problem.

Turn out to be bad counter IC.  I replaced both. Working now!

 

Derek

[auric]

I don’t have any additional suggestions.

My original thought was that the residue from the foam could be creating a short or adding some resistance hence higher signal goes through. But if the PCBs are all clean the fault is somewhere else.

 

[auric]

Rolf:

Just a quick tip when using polishing wheels. Be very careful when using and do not leave on one spot for too long. The friction can develop a lot of spot heat and melt the plastic.

Patience is key! Slow and easy. “Haste makes waste” 🙂

Re the gouges those can be removed wet sand paper. Grittier to first remove the gouge and then finer and finer grit to get it back to a polish.

Derek

[auric]

Thanks Martin, appreciate it as always. It’s been a long time since I owned one of these.

The butterfly tuning indicator works.

Derek

 

[auric]

The damping material has been known to degrade in Beolab 8000. Possible it has become conductive and shorting out some of the circuitry?

[auric]

PCB 60 which is the board mounted across the heat sink on the back of the unit.

There is one connector with a pair of wires. P80 or P81. Those powers the motors.

The traces on that PCB are very thin and fragile. Lots of cold solder joints and cracked/peeling traces especially where the connectors terminate and speaker muting relay.

Reflow the connectors and make sure the traces are not cracked.

[auric]

Ipe:

There should be a red standby led when you plug the unit in.

The powerlink has a 5v trigger which comes from the Beocenters and tells the speaker to turn on at which point the led changes color to green. So for it to play you need to send an audio signal as well as the 5V trigger.

 

But if you are getting absolutely nothing… start with the power supply.  Maybe a fuse?

Is the cord plugged all the way in? The receptacle is in a very awkward location and its  not always easy to plug the cord in properly.

 

Derek

[auric]

So here’s my guess.

The tone arm is mounted on sled that is driven by long threaded rod.

Unlike the 8000 series turntables, the threaded rod is not fixed on both ends and so can become mis-aligned.

The rod is held in place only on the right end of where it is terminated by a bracket and pulley (where the sled motor is). If the bracket has come loose and the rod is misaligned then what happens it the sled can only go partially across the record.

The sled rides across a fixed polished rod. The fixed rod and the threaded rod needs to be reasonably parallel across to each other. If not at some point the divergence between the two becomes to great and so the sled can no longer move.

 

 

 

 

 

 

[auric]

Martin:

Is there a scenario with an intermittent switch that can set the volume to 1111?

When the unit is misbehaving, the volume appears to turn on at full. The  volume indicator light is fully lit on the right and is receiver is at max volume.

I checked the preset switch and seems fine. The is one of the newer units with the molex connectors to the tone control board.

Derek

 

[auric]

This thread may help:

https://archivedforum.beoworld.org/forums/p/37009/306632.aspx#306632

Check the archived forums. Lots have been written about this.

Derek

[auric]

Luigi:

Maybe you need a new belt.

Take the top plate off. The tone arm motor is located in the upper right hand corner of the deck.

If the pulley is motor is turning but the pulley is not then the belt is slipping and will need to be changed.

 

Derek

 

 

 

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