This post describes the functional restoration of the Beogram 8002 (Type 5633) that I recently received from a customer in Massachusetts. This unit also received a Beolover Beo4 enabled Commander Remote Control for Beogram 8000 and 8002. A great way to integrate a Beogram 8002 into an existing B&O setup. My initial assessment of this Beogram is posted here.
Here is an impression of the final result of my efforts:
Let's see what it took to get there:
This shows the Beogram in 'service position', i.e., with all functional parts removed from the enclosure. I usually put everything on my Lazy Susan, which lets me work on it from all sides without having to move the delicate setup:
I started by rebuilding the main PCB. I unplugged it from the wire harnesses:
I removed the microprocessor can and started working on replacing all the electrolytic capacitors.
Here is a detailed shot of the large reservoir capacitors:
The main reservoir capacitor on these boards has a 'historic' 4-pin package, which is no longer manufactured. I replaced it with the Beolover 4-Pin 2200uF Reservoir Capacitor for Beogram 8000 and 8002. This shows it in comparison with the original part:
This shows the rebuilt reservoir capacitor section:
I also resoldered all the board headers. They tend to develop intermittent solder joints due to mechanical and thermal stresses.
There is one important capacitor inside the microcontroller can. It is responsible for decoupling the processor power supply from the motor noise on the power rails. This shows the can with the top lid removed:
Like in maybe a third of all cases, the microcontroller came off together with the lid:
The thermal compound often is strong enough to extract the package from its socket. Usually this is not a problem. Just remove the processor from the lid and stick it back into the socket before replacing the lid. It is actually good if the processor is not in place while working on the setup, so there is less chance that static charges damage the IC.
The capacitor is located under the small piggybacked board. Pulling the board up usually reveals some insulating tape and the capacitor:
Sometimes the insulating tape covers the capacitor, too. In this case it did not.
The interesting aspect of this capacitor is that the negative lead is soldered to the board on both sides, i.e., it acts as a via. In the 1980s, they did not yet have through-plated vias on consumer product-level PCBs, and so they used through-hole component leads as 'convenience vias'. Since one cannot get to the top solder of the negative lead without doing some damage, it is best to unsolder the positive lead first
followed by breaking off the other lead from the capacitor can by rotating it until the wire breaks.
This is how the board looks from the bottom after removing the bottom lid from the can:
It is best to remove the tacked-on shielded wire before removing the capacitor. This shows it after pulling up the insulating tape:
I removed the wire:
After removing the broken-off wire stump, the new capacitor can be soldered in with the negative lead first:
This shows it in place with the processor back in place:
After tacking the wire back on
and putting the lids back, I installed the assembly on the board:
If you do this at home, make sure that the wire leads of the ribbon cables are properly inserted into the header underneath the board. It is easy to get adjacent wires into the same female header position. If this happens, 'interesting' effects on the turntable operation occur!...;-).
After completing my work on the main PCB, I exchanged the capacitors on the voltage regulator board next to the sub-platter. This shows the original capacitors still in place:
And with the new capacitors in place:
It is a good idea to remove the tacked-on wires before replacing the caps. This prevents potential damage to the wire insulation with the soldering iron.
An important capacitor that usually needs replacement is the phase-shift capacitor in the transformer block. This shows the replacement block that I had in my stash without its lid:
It turned out I had already replaced the original capacitor with the Beolover Motor Capacitor for Beogram 8000 and 8002. The Beolover replacement part uses modern multi-layer ceramic capacitor arrays, which are 'natively' non-polar. A much better solution for use as a phase capacitor! The part fits neatly next to the fuse and contact terminals assembly. The Beolover part can be used for both 50 Hz and 60 Hz versions of the transformer block. Depending on the frequency, the phase capacitor has a different value. Simply solder one of the two wires to the appropriate capacitance terminal and the other to the COM pad.
Next came the replacement of the output relay. This shows the bottom side of the DIN7 jack output assembly. The relay is concealed by a clamped-on shield:
Pulling off the shield reveals the relay:
I replaced the relay with a new one: The new one has the same form factor as the original one, so the shield clamps back on without a problem:
As usual, I also installed a (red) switch that allows connecting the signal and system grounds:
Connecting both grounds usually quenches any hum when connecting the Beogram to an amplifier.
The next step was to replace the incandescent light bulb in the <</>> button assembly on the PCB that is clipped to the back of the keypad. This shows the keypad with the PCB still installed:
The light bulb is in the black box mounted to the board. Its replacement requires the removal of the board from the keypad. After lifting up the board with a suitable screwdriver on the right side so
that it can clear the locking plastic feature, it can be slid out to the right.
I usually take this moment as an opportunity to clean
the keys and their recesses in the plastic panel. The keys come off easily after the PCB has been removed:
Make sure the keys are in the right order when reassembling the keypad after cleaning everything.
I usually clean the keys with a moist Mr. Clean eraser pad. Don't use the pad on the LED display cover. It can scratch the plastic! A lens cleaning cloth is perfect for cleaning the LED cover.
The plastic panel is best cleaned with some warm water and dishwashing soap. Never use alcohol on Beogram 8000/8002 components.
After this cleaning excursion, it was time to replace the bulb. This shows the black box with its lid removed:
The bulb is in the center of the assembly. The two whitish components, left and right, are photoresistors. When pressing the << or >> buttons, the amount of light impinging on the resistors changes by means of two apertures that are moved with the buttons. This allows the gradual adjustment of the carriage speed depending on how hard the <</>> buttons are pressed. Nifty!...;-).
This shows the white light 5 mm LED before installation:
The LED needs to be Dremelled a bit to roughen up the surface of its plastic bulb and to reduce its diameter slightly. This ensures the LED fits and that the light is dispersed homogeneously onto the photoresistors. LEDs emit a more directed light pattern compared to incandescent bulbs.
This shows the LED installed:
The light bulb runs on 15 V. Therefore, a suitable current-limiting resistor needs to be connected in series with the LED. I usually solder it on the 15V side:
If you try this at home, make sure the resistor is approximately in the location shown in the photo above. Otherwise, it is possible that it will interfere with the plastic panel when the board is reinstalled behind the keypad.
My customer wanted a Beolover Commander Remote Control for Beogram 8000 and 8002 installed. Installation requires removal of the angled board header and the grey ribbon cable from the board:
Next, the header and the cable need to be transferred to the Commander PCB:
]
The Commander PCB itself gets soldered to the main PCB:
After replacing the cover of the black box,
I focused on the carriage assembly. I removed the carriage rods and spindle parts for cleaning. As usual, they were encrusted with old, hardened lubricants:
I put them into my ultrasonic cleaner.
The bulb sits in a small compartment under the arms, which is covered with a piece of sheet metal:
The cover can be slid out to the left after it is lifted a bit up with a screwdriver to clear the locking feature:
This reveals the whitish photoresistor on the upper side of the grey tracking aperture and the light bulb below. Both parts are mounted on a small PCB. The exchange of the bulb requires the extraction of the PCB. The PCB is connected to four leads that come in from the bottom of the tracking sensor compartment. This shows the bottom view with the wiring. The wires are held in place with a small rubber ring stuck onto a plastic nipple:
Removal of the rubber ring allows pulling the wires out of their conduit:
This is necessary to give the wiring some slack so that the small PCB can be pulled out a bit to access the solder pads of the bulb.:
This is how the board looks from the component side:
I removed the bulb. This shows it together with the Beolover LED assembly:
This shows the LED assembly soldered to the bulb pads:
The board is in the correct position when the end of its narrow part is flush with the solder side of the PCB. Also, make sure the LED is facing the photoresistor (;-) if you try this at home:
I pushed the board back into place:
Then I stuck the wires back into their conduit and replaced the small rubber ring:
While the carriage is 'up', it is the only moment the vertical arm can be adjusted. The screw can only be accessed when the carriage is liberated from the rods.
But before I could do the adjustment, I had to glue a piece of Kapton sheet to the bottom of the counterweight where the adjustment screw touches:
This prevents the screw from sticking to the counterweight during arm lowering. This can sometimes result in undamped and delayed arm dropping when the screw sticks, while the arm lowering mechanism has already released the arm. After putting the Kapton piece in place, I adjusted the arm vertical parallelism:
Simply turn the screw until the arms are parallel:
In the meantime, the carriage components came back from the ultrasonic cleaner:
I put everything back together. It seems the best way is to first put the longer rod in place together with the plastic 'fork' that connects the white nut on the spindle with the carriage, and then insert the spindle with the nut approximately in the center, as shown here:
Then simply tilt the carriage towards its horizontal position while inserting the other end of the spindle into its ‘bearing’. Once the spindle is in place, the shorter rod can be inserted and locked into its cradles.
At this point, everything was back together, and I adjusted the 'idle voltages' of the <</>> assembly. Both left and right voltages need to be ~620 mV when the buttons are not pressed:
This voltage is adjusted by turning the screws on the black <</>> box on the keypad PCB in or out.
After this adjustment, I replaced the original carriage motor with a new Carriage Motor for Beogram 8000 and 8002. The Beolover motor runs more quietly with less vibration and also draws less current for the same performance. This shows the original motor together with the Beolover replacement components after opening the clamshell motor enclosure:
Installation is easy: Insert the new motor without the alignment pieces. Then solder the blue wire to the terminal not marked with a dot and the provided piece of blank wire to the one marked with the dot
Then put the alignment pieces into place so the motor is aligned. Then cut the blank wire to an appropriate length and connect it to the brown wire end:
Now the enclosure can be closed again. This shows it from the pulley end with a
new carriage belt installed:
Then I adjusted the tracking feedback. This is done by adjusting the aperture position inside the tracking sensor housing. The aperture is moved by a screw on the side of the housing:
The feedback should be adjusted to get about 2-3 platter rotations before the carriage motor starts running after the needle is down.
And finally, it was time to give this functionally restored Beogram 8002 a first spin! I selected a great recent addition to my collection: 'Collaboration', which was released by George Benson and Earl Klugh in 1987. I seem to have the original US release on Warner Bros. Records (
925580-1):
The Beogram played perfectly!
I played it in the service position for a couple of weeks until I received a new dust cover fitted with the original black "Beogram 8002" labeled trim. Co-Beolover Beomazed figured out a while ago how to transfer the original labeled hood trim to a new reproduction hood. A much happier solution than using the unlabeled black trims the DKsoundparts store sells. The original labeled trim on a new hood definitely helps give a Beogram that sharp 'like-new' look!...;-).
After I had received the new hood, I put the Beogram back into its enclosure. When I seated the PCB, I realized where the plastic piece came from that I had found in the box when I received the unit:
It was one of the two 'hooks' that hold the PCB in place on the transformer end. This shows the area where the piece broke off to the right of the rectangular opening:
I decided to try to fix it instead of ignoring it, which might have been possible. But since the transformer end of the board needs to be able to withstand the transformer block being pushed onto the board header, this hook is actually a bit important. I drilled a hole through the broken-off piece
and into the enclosure:
The plan was to use a small 2mm self-tapping screw to reinforce the epoxy glue I would be using:
I added a screw head recess, so I was able to get the screw sufficiently far in to have enough turns into the hole in the enclosure:
This shows the piece back in place with some epoxy added at the fracture:
After the epoxy had hardened, I put the board in:
Like it never happened! Beolovely!
On to another issue: This unit came with one of the leaf spring hooks unhinged due to a missing wire piece. This gave me the idea to design 3D-printed receptacles for the hooks:
It turns out that these are actually a nice improvement over the original setup since they cannot liberate themselves after the wire hook is in place. This makes it much more straightforward to hang the sub-chassis back on the leaf springs.
Now it was time to glue the aluminum plates back into place and install the new hood. First I needed to remove the deteriorated double-sided foam tape they used back then to attach the parts. I usually soak some cut-to-size paper towel strips in isopropyl alcohol and then put them on the tape spots:
The other half of the tape remnants is usually on the aluminum plate, so it is convenient to catch them too by putting the plate in position on top of the paper towel. This also reduces evaporation, so the soak can last a bit longer:
Once the tape remnants were removed, I glued the plate into place with some epoxy. I used carpenter clamps and a mallet to hold things together while the glue hardened:
With the plate back in position, I installed the Beogram back into the enclosure. This unit also had a leaf spring that had been mutilated for whatever reason. Someone felt the need to Dremel the slot for the adjustment screw a bit wider. This shows the damaged piece together with one that I found on ebay:
Then I installed the new hood, and then it was time to attach the aluminum lid back to its hinge. I usually do that with double-sided tape:
The final step was gluing the metal shield back under the small black panel that sits under the arms. I usually also use double sided tape for this task:
This shows the plate reattached:
Then it was time for a test spin of the fully assembled unit:
I selected an old favorite of mine that I had bought in the 1980s: "ein deutsches album" by Peter Gabriel. He released it in 1980 on the Charisma label (
6302 035). Here are a couple of impressions of this interesting album playing on the newly restored Beogram:
The Beogram 8002 performed perfectly. So it was time to take a bunch of nice pictures of it in my photo studio to celebrate this successful restoration!
Enjoy:
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