ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I have been wanting to work a Beogram 8000 restoration project for over two years now but kept getting derailed by other things. Now that I have several Beogram 8002 projects under my belt and a few Beogram 400x projects finished, it is time to get at least one Beogram 8000 turntable working in my home.Two of my Beogram 8000 turntable candidates were from system purchases I made over the last two years. A third turntable is one I found for a good price on Ebay.All three BG8000 turntables were acquired in non-working condition. I also collected some of the Beogram service and technical manuals so I think I am ready to start.
The three Beogram 8000 units are in various states of disassembly. My goal is to get at least one functioning and ideally, all three. However one of the turntables came with broken tonearm wires. I used that tonearm to learn how to remove the cartridge mount in my Beogram 400x thread (using Martin's boiling water technique). Since that repair will be the most difficult it moves it to the end of the line. I will pick one of the candidates that has the most chance of success to be first. Here are some of the parts removed from the three Beograms. All three also have bad tacho discs. I have one of Martin's metal tacho disc replacements so I will order additional discs if the chance of repairing more than one turntable is possible.
Here is one of the Beogram tach discs that is actually in decent shape. It is starting to peel though so it needs a metal disc replacement.
This Beogram 8000 tacho disc is really shot.
I noticed that two of my Beogram 8000 turntables are fairly close in serial numbers and have the same kind of tach sensor.
The third Beogram 8000 is a later serial number and has a slightly different tach sensor assembly.
My next step is to decide which of the turntables with good tonearm assemblies I'll start with and I need to go through the circuit boards to see if I have all of the replacement capacitors in stock. Hopefully I can start working on the first Beogram this week.
-sonavor
I'm looking forward to this thread, I can't get enough of the 8000 series 👍
while your in there check the condition of the 3 optos , 1 under the tone arm and the 2 inside the keypad, one of my machines the silver coating had faded so measured working but were no longer doing thier job well enough and adjustments couldn't compensate .
replacing all 3 worked wonders.
Regards Jason
Jason : while your in there check the condition of the 3 optos , 1 under the tone arm and the 2 inside the keypad, one of my machines the silver coating had faded so measured working but were no longer doing thier job well enough and adjustments couldn't compensate . replacing all 3 worked wonders. Regards Jason
You are referring to the photo resistors 5R1 (for the tonearm) and R9, R10 (for the keypad)? Where did you get your replacements?
Yes the photo risistors, the ones I used were just what I had in stock at the time, smaller than the original but worked perfectly.
bought from cpc , code re04698
regards Jason
I don't know if I was just lucky but once installed I didn't need to do a single adjustment on the screws, perfect function was just instantly restored
jason
One of my Beogram 8002 turntables has a problem with those adjustments. It is the only one I have had an issue with regarding those but I never inspected those photo resistors. It sounds like they are probably the root of the problem on that one. I will definitely check them on these Beogram 8000 units.Thanks for the information.
Looking over the Beogram circuit boards there are also two almost identical and one different.The main differences are on the microcomputer board. This picture shows the microcomputer board on the left not having the modification for turntable speed variation that the microcomputer board on the right has. Two of my boards are like the one on the right.
One of my service manuals contained an addendum page describing the modification.
So what I have are two earlier Beogram 8000 turntables. One of them has modifications per the service manual addendum. Then I have the newer Beogram 8000 turntable that has the changes as they were incorporated in the production line.Here is the trace side of the oldest main board next to the later main board.
Here is the other older board with the modifications to bring it up to later production models.
A closer look at the modified board shows that the Periodical Variation of Turntable Speed fix was added on versus the other Beogram 8000 where the change was more integrated into the microcomputer board (from the factory).
I had to order a few 2200uF, 16V and 4.7uF, 100V capacitors as well as some 40 pin DIP sockets (to replace the old ones for the microprocessor). Everything else I had plenty of stock so I am ready to start working on the first Beogram. I think I will restore the newest serial number turntable first as it has all of the factory integrated modifications.
Here is what the motor control photo resistors, lamp and light control assembly looks like inside for controlling the forward and reverse.The two big adjustment screws fit on either side of the lamp so their height blocks or allows light to pass to the photo resistors. I had always thought the adjustment screws were moving some internal part for the sensitivity adjustment but it is just the position of the screw that is doing the job.
The boards needing recapping were already removed so I unsoldered the existing electrolytic capacitors. To begin the recap, I started with the microprocessor module. It has one electrolytic capacitor (C28) that needs replacing - 47uF, 10V and I want to replace the old processor socket.
Here is the old and new processor socket
This is the processor module after the new parts are installed.On some of my Beogram 8002 restorations I had to replace the 4.7nF capacitors for the display. They are small and difficult to get to because of space and they are soldered on both sides of the board. I think I will leave these alone for now and see if the display works when I get the board ready for testing.
When I recapped the main board I kept the grounding ring for the large, 2200uF capacitor to use with my replacement. That makes it easier to attach.
Here is the recapped main board. I also replaced the 180 ohms (R104) resistor.The next step is to resolder all of the connector joints. Those can cause problems and these Beogram 8000 main boards I have are all slightly curved.
I have now resoldered all of the main board connectors and switched out the two 1uF capacitors that were mounted on the trace side. There are now just a couple of capacitors to check on the chassis before I can reassemble the turn table for a check of the board reword. If that goes well I will be able to start in on checking the tangential arm assembly.
I do enjoy your threads john 👍👍
It's a wonderful deck once restored and as perfect as i think they look, I wish sometimes the flat top of the lid was angled up to match the rest of the 8000 system
might be just me though😄
Thanks Jason. I think I will always prefer the look of the original 400x series but I have owned a Beogram 8002 since 1983 and really love the performance of that series. This Beogram 8000 should be the same except I can use the MMC 20CL and MMC 6000 cartridges in it.
This picture shows how badly curved the main board is with this Beogram. It is recapped and I am close to running some tests with it but I am wondering if there are any hidden surprises with this board.
I re-installed the processor in the new socket. It fits very snug.
It is time to move on to the main chassis. There is quite a bit of dust and grime so I will dissemble the tonearm assembly and recap OC1 and OC2.
Here is 0C1 and 0C2 before the recap. This step is pretty much just like the Beogram 8002.
I think it is easier and safer to remove the main (floating) chassis to clean and work on the various components.
It is hard to seen in the pictures the film of grime on the turntable. I removed a lot of the components so I could get to everywhere I needed to clean and lubricate.
This part shows recapped 0C1 and 0C2 after cleaning the floating chassis.
I removed the tonearm assembly from the rails and the drive shaft for cleaning and maintenance. There was a lot of grease build up in spots. On my Beogram 8002 project Martin pointed out that the bottom rail has a rubber insert that the rail ends fit into before going into the mounting sleeve. That is for some vibration damping on the USA voltage. This Beogram 8000 has those rubber pieces so I cleaned them and applied some rubber conditioner.
While the tonearm assembly is disassembled, here is a picture of the tonearm assembly underside.
The main chassis is now cleaned up, 0C1 and 0C2 recapped and the tonearm assembly lubricated and put back together.
Here is the front view. Later today I will get the main components connected and test if the recapped main board is working.
A couple more things to do before trying out the reworked board and chassis. I opened up the control panel keypad and it was pretty dirty.
Easy to wipe down and clean the inside. I also removed the buttons and cleaned the slots they fit in.
I learned from my Beogram 8002 restorations not to use isopropyl alcohol to clean the inside, black chassis. The alcohol melts the black paint. However, some drops spilled onto my Beogram 8000 chassis as I was cleaning the keypad. I will have to touch that up later.