Beogram 8002: Final Wrap up

Today is the final day here for this Beogram 8002 turntable. Tomorrow it will return to its owner to enjoy. I have spent two days now playing records on it while I work in my office. This Beogram is functioning perfectly.

Last night I started on the lid assembly for this turntable so I could attach it today. I discovered that the black, metal base in the tonearm compartment had a problem. It turns out someone previously attempted to repair the underside where Bang & Olufsen also originally used double-sided tape.

The original tape deteriorates by now and can no longer hold pieces together. Instead of cleaning all of the old tape residue off another piece of tape was installed. It has now come loose.

No big deal. I just pulled the current tape off and used some Goo Gone to help get rid of the original tape residue.

I like to use 3M double-sided tape for this repair. I cut a few strips to customize the fit and reattached to the pieces.

Now I can focus on the dust cover hinge. Here is the original hinge for this Beogram.

It is missing the black plastic trim piece that hides the metal hinge from view. There was a bunch of dry, pasty grease residue so I had to clean all of that up and re-lubricate the hinge pivot.

Once I get into this part of the restoration I tend to not think about things like taking pictures so I forgot to get some detailed shots of this Beogram's hinge assembly. I do have pictures from one of my previous restorations of this hinge so I will use those to show what the dust cover hinge attachment is like.

Here is what a Beogram 8002 hinge assembly typically looks like when first opened up. The hinge clip that mounts to the lid was originally attached with some double-sided tape that eventually gives out. On this Beogram project I re-attached it with some epoxy. These pictures also show the hinge trim cover piece that this Beogram is missing.

The lid hinge and lid clip slide together to form the completed dust cover hinge.

The metal part of the hinge assembly is mounted on the leaf spring and there is an allen screw to adjust the amount of spring force to keep the lid raised. Note that you actually attach the hinge assembly to the leaf spring bar prior to attaching it to the lid clip.

For this Beogram project I was able to find a spare hinge assembly trim cover so the dust cover assembly looks much better now.

I also re-installed the owner's SMMC3 cartridge and adjusted the tracking force to the recommended 1.2 grams.

This turntable is ready for one last test play.

I decided to pull out an old Renaissance "Song For All Seasons" LP from 1978 and give it a spin.

Very nice 70's progressive rock sound. I believe this turntable restoration is complete.

Beogram 8002: Taking the restored turntable for a spin

The last bit of repair on this Beogram 8002 is to fix the problems with the dust cover lid assembly. Meanwhile I started playing records on the Beogram as a test drive (or burn-in test). This is always the best part of the restoration.

I set up the Beogram 8002 in my office so I could listen to it play for the next couple of days. One of my kids is a trumpet player so I find myself listening to a lot of music by trumpet players. This picture is the Beogram playing Freddie Hubbard's First Light  LP. My copy has a very slight warp in it but the Beogram had no problems tracking it.

Once the listening tests are over and the dust cover assembly is re-attached this Beogram will be returning home.

Beogram 8002: Service Manual Adjustments

Going in to the Beogram 8002 service manual adjustments I already know that the fixed arm and tonearm horizontal parallelism needs adjusting. The tonearm appears higher than the fixed arm as you can see in this picture.

The tops of the two arms should be the same height and that height should be 19.5mm from the top of the Beogram platter. So the fixed arm needs to be adjusted up and the tonearm needs to be adjusted down.

To make all of the necessary adjustments I have to get to the underside of the tonearm carriage assembly. That means removing the rails and the tangential drive screw. I have to do this anyway to clean and re-apply some lubrication.

The red arrow in this picture shows the adjustment screw for the tops of the arms (the horizontal parallelism adjustment). The green arrow is for the vertical parallelism adjustment (the gap between the two arms). I am pointing that out as it turned out I needed to adjust it as well.

After adjusting the horizontal parallelism I got both arms to the 19.5mm height from the platter surface.

I installed a new tangential arm drive belt.

I also cleaned and checked the lubrication of the platter hub. The following pictures show the Beogram from platter hub removed to the sub-platter re-installed. I was able to find a spare tonearm assembly cover trim piece. The original one was missing from this turntable and the wires were exposed.

When I put the top platter back on and connected the main board the tonearm and platter worked okay but I noticed something was not right with the tonearm. When the Beogram 8002 tonearm is at rest you should be able to push the arm towards the fixed arm and have it spring right back to centered position when you let go. With this tonearm I was detecting an obstruction that was hindering the spring back action.

I was concerned at first because I couldn't see anything wrong. The vertical parallelism looked correct. I took a peek into the tangential arm tracking sensor assembly.

Note the spring clip in the picture below. That spring mechanism moves the tonearm back to a centered position when you move the tonearm away from the fixed arm.

Everything was fine in there. Nothing was scraping.

I finally realized the tonearm vertical parallelism adjustment screw was the problem. It had been adjusted incorrectly. While the gap between the fixed arm and tonearm looked fine, the tonearm raise/lowering bar was not operating correctly in the V-shaped channel of the brass adjustment screw.

The following picture of one of my own Beogram 8002 turntables shows the tonearm lift/lowering bar and the V-Channel adjustment screw. The lift bar has a spring mechanism that will attempt to keep the bar pressed down on the V-channel when the arm is in the raised position (not playing). If you manually move the tonearm towards the fixed arm the lift bar rides up one side of the V-channel. When you let go the tonearm should pivot back to a centered position as the spring loaded lift bar returns to the bottom of the V-channel.

On this Beogram 8002 project turntable the lift bar was getting slightly stuck at the top of the V-channel screw when the tonearm was moved towards the fixed arm. By re-adjusting the V-channel screw (which is the vertical parallelism adjustment screw) I was able to get the tonearm back to its normal, springy self.

The tonearm and fixed arms are also vertically parallel to each other.

I test played one complete side of a record and observed the linear tracking working correctly as the stylus remained always centered. I could see the tangential arm assembly motor adjusting the tonearm position pretty much ever half turn of the record. Very nice results after all of that disassembly/reassembly of the Beogram mechanics.

The last check I wanted to make was the voltage level of the light driven sensor in the control panel. This is for the Beogram forward/fast forward and reverse/fast reverse function. After the Beogram has been operating for at least five minutes the voltage of the forward/reverse sensor should be around 620mVDC in its normal state. This check is done my monitoring control panel connector P5-4 to P5-3 (ground) and P5-6 to P5-3 (ground). To adjust the sensor voltage levels there are two screws on the control panel that operate an aperture for the sensor lamp source as seen in the picture below.

The procedure requires checking the voltages at both test points a few times as each screw is adjusted. Each adjustment screw can affect the measurement at both test points. After a few iterations I got the sensor to a satisfactory level.

Tomorrow I will re-assembly the Beogram 8002 (except for the dust cover lids) and do some actual record playing testing.

Beogram 8002: Recapping Complete

For the replacement of the electrolytic capacitors I will pick up where I left off...with the Beogram 8002 transformer box that I opened up. The 27uF capacitor for the motor circuit will be replaced using Beolover's nice 3D printed assembly. I like to measure the old capacitors to see how many are bad, out of tolerance or on the verge of being out of tolerance.

The original 4C1 27uF capacitor of this Beogram is out of tolerance by almost 20%. 

The replacement part just drops into the transformer box and the two leads soldered to the new 4C1 27uF capacitor. This is a bipolar capacitor so it doesn't matter which wires to connect to the capacitor module leads.

That is way better than soldering a new capacitor and letting it dangle loose inside the transformer box.

The next capacitor is the 2C28 47uF capacitor in the microcomputer case. I cleaned off the old thermal paste (that was starting to dry out) from the microcomputer integrated circuit and the heat sink. The 2C28 capacitor was replaced and new thermal paste was added to the heat sink. The replacement of the 2C28 capacitor is a little tricky as the negative side of the capacitor must be soldered to the board on both the trace side and the component side as noted by Beolover a while back.

For the Beogram 8002 main board I replaced all of the electrolytic capacitors 2.2uF and less with WIMA MKS capacitors (the rectangular, red capacitors in the picture). The rest were replaced with new 105°C, long lasting electrolytic capacitors. For the large 1C27 2200uF, 50V capacitor I like to use the three prong base off an original Beogram 1C27. I had a spare base so I used it here.

The center hole is for the capacitor positive lead. I take the capacitor negative lead and solder it to the metal base. After that I use black hot glue to secure the rest of the capacitor to the base and place it on the board. This makes for a solid installation of this capacitor like the original.

The last two capacitors are on the Beogram 8002 chassis - 0C1 and 0C2. These are easy to get to. Just remove three wires (the yellow, black and blue).

The next picture shows how close together traces are on the Beogram 8002 main board. When re-flowing the solder joints of the board connectors it is best to use a smaller tip on the soldering gun. If the tip is too wide it is really easy to accidentally create solder bridges between traces. I have to use a magnified lamp when soldering on this board to tell if the result is good.

That completes the electrical restoration of the Beogram. A quick check of the work with the Beogram turntable assembly verifies that everything is good.

Now it is on to the service manual adjustments which will make sure this Beogram is ready for full use again.

Beogram 8002: Preparing the Restoration

The decision has been made to do the full restoration on this beautiful Beogram 8002. The first step is to open it up for service and prepare the parts for restoration.

These early eighties Bang & Olufsen audio components were designed to open up for servicing similar to an automobile hood. The modular design makes it nice to work on. There are still some tricks to learn in properly opening the units up and some out of the ordinary tools are a big help.

I already removed the dust cover and tonearm compartment lid assembly. I need to check why the alignment is off on that later so by removing it the lids won't accidently flip open and get damaged when the deck is tilted up.

To get the Beogram deck open there are only two screws underneath the left side that have to be removed. However, to open the deck up you must carefully detach the three suspension springs and when the deck lid is tilted up you have to maneuver the platter assembly to the right slightly. The reason for that is there is the deck cannot clear the tonearm assembly unless the platter assembly that holds it is shifted.

Here is the Beogram with the deck lid up (dust cover and tonearm compartment lid assembly already removed).

As noted in the photo, with the Beogram open I discovered another missing trim piece. There should be a black plastic cover for the exposed wiring board on the tangential arm assembly. I will look for a spare or fashion one out of a sheet of Dura-Lar.

Turntable adjustments and tests can be made with the Beogram opened up in this service position. For restoration work though I fully remove the Beogram assemblies so they can be worked on individually or connected together and tested.

This picture show the Beogram 8002 assemblies removed from the case and operating.

When I had first examined this Beogram I noticed the horizontal parallelism of the reference arm and tone arm was off. The tops of the two arms should be the same. In the picture below you can see the tone arm is slightly higher. The service manual has a procedure for adjusting that and it requires taking the tangential arm assembly out to get at the underside. That isn't a big deal as I was going to lift out the arm anyway to check the lubrication of the tangential arm drive.

Besides the service manual mechanical adjustment procedures this restoration will rework the Beogram 8002 main board. The electrolytic capacitors will be replaced and solder joints re-flowed on all of the board connectors. Here is the Beogram 8002 main board opened up.

...and inside the metal box with the microcomputer.

There is also a capacitor Bang & Olufsen engineers mounting in the transformer box. This capacitor is a coupling capacitor for the platter drive motor. It is obviously too big to have fit on the main board or on the platter chassis so it was put in the transformer box.

That is it for preparing everything for this restoration. It is time to start the work.

Beogram 8002: New Arrival

Today I started looking at a Beogram 8002. The original owner had the original B&O shipping box and was able to hand deliver it to me. That is always a bonus when shipping can be avoided.

This Beogram 8002 is reported to have some issues with the initial tonearm set down position and play time (especially when cued forward on a record). There might also be some cosmetic work needed and possibly the usual restoration updates on these turntables at this point of their life.

Time to inspect this unit and see what state it is in.
The Beogram was properly packed and the suspension was locked down.

Lifting the cover I found the top platter to be in exceptional condition. It has been well taken care of.

Removing the platter and its packing material I found the first odd thing with this unit. The front suspension spring has an additional washer and some glue. I am not sure why that was put there. Obviously this unit has been worked on before.

The inside and back reveal the dust cover and tonearm compartment lid have also had work. The lids are in good shape overall but they don't fit quite right. Looking at the back I can kind of see why. There are attachment screws added (red arrows in the photo) to keep the Beogram cover on. I am not too surprised by this. As much as I personally like this model of Beogram it does have a design weakness when it comes to the lid. While it looks great the lid originally attaches to the Beogram chassis using plastic tabs (yellow arrows in the photo). These often break off over time resulting in a dilemma of how to attach the dust cover. The choice of screws makes sense but there is some problem here with the final alignment of the lids.

Another problem with the dust cover is the black plastic cover (blue arrow in the photo) for the dust cover's spring hinge is missing. There are glue remnants so tabs probably broke off the original.

The original black plastic cover on the dust cover lid hinge looks like this.

I might have a spare in my parts bin or maybe this is a new candidate for a Beolover 3D part.

For some reason the control panel was loose already so I took a peak inside.
Inside I can see that the three larger power supply capacitors were already replaced by someone. That makes sense as that is a typical problem. When the repair was done it was probably much earlier than the present so a full recapping of the electrolytic capacitors was not performed. The top part of the following picture shows this Beogram power supply section of the main board. The lower part of the picture shows what an original state main board looks like.

Now that I had a chance to look over the Beogram I decided to give it a spin. This Beogram came with an MMC2 cartridge mounting on the tonearm and a SoundSmith SMMC3 spare cartridge. I will check out both cartridges while it is on the bench.

First though I had to set the tracking force as the slider had slid up to the maximum 2 grams of tracking force. The MMC2 should be able to track at 1 gram so I adjusted it.

Using a test record I check the Beogram with the already installed MMC2 cartridge. My QA400 audio analyzer showed activity on both the left and right channels but as the owner reported, the Beogram would suddenly stop playing. I pulled out the black panel in the tonearm compartment so I could observe the tangential arm assembly tracking sensor module. The tracking sensor lamp was illuminated so that check is okay. Next I removed the top platter again so the tonearm would lower into blank space as if a record was present. By gently nudging the tonearm towards the center of the turntable I simulated the tonearm moving inward as if playing a record. I could see the tangential arm motor turn to keep up with the movement.

So the usual quickie tests looked good but the turntable had exhibited faulty tracking. I put the platter and test record back on and tried a track half way in on the record. Quickly I noticed the stylus and cantilever of the MMC2 bend inwards with the tonearm not moving so I raised the arm and stopped play. That looks suspiciously like a cartridge problem.

I switched to the SMMC3 cartridge which is obviously a much younger cartridge. I pressed the play button and observed the Beogram play the test record from start to end where it lifted up and returned to standby position as expected.

Here is a picture of the SMMC3 cartridge test. You can see the tracking sensor lamp illuminated underneath.

It is possible then that this project will be a quick clean, lubricate and service manual check. I will need to test the suspect MMC2 cartridge in one of my own Beogram 8002 units to double check. The service manual checks should expose any other hidden problems. It does appear that the tonearm height may need checking. I also need to find out what is wanted regarding the cosmetic problems with the lid alignment.