Beogram 4002 Type 5513: Third Beogram From Houston Restoration Continues

The Beogram 400x Bonanza continues as I completed one Type 5513 turntable and move on to the next one. This one continues a owner in Houston's third Beogram 4002 Type 5513 turntable restoration.

As I showed in the initial assessment back in March, this turntable is in nice shape and a great candidate for restoration.

Like the previous Beogram 4002 Type 5513, I already had Beolover restore the platter motor of this turntable and have it ready to be put back into service.

I decided to start the rest of the restoration on this Houston Beogram 4002 with the electrical work...recapping the usual two boards, changing the two relays, replacing the platter speed trimmers and preparing the added trimmer for the eventual record detector circuit checks.

Here is the main board before the restoration steps.

I went ahead and prepared the trimmer replacement for 1R26 and checked the current gain of the 1TR3 transistor (the two components that we look at for the record detection circuit).

The transistor measures great.  I removed the original, fixed resistor 1R26 and fit the replacement trimmer.

That is where the trimmer will eventually go.  For now I will temporarily fit it on the trace side of the board where I can make the initial adjustments later.

I took a look at the 1C10 resistor that affects the platter motor stability.  The previous Beogram 4002 Type 5513 turntable restoration had a 33uF capacitor for 1C10.  This turntable has a 0.47uF capacitor.
I won't change the value on this one but it is interesting to note the difference.

Finally, here is the platter speed selection relay and the two speed trimmers of the original board. All three will be replaced.

Here they are replaced with a Beolover replacement relay and two muli-turn trimmers.

...and here is the main board after the electrolytic and tantalum capacitors have been replaced.

The next board is the output board. This is the board where the phono cartridge audio signal exits the Beogram.  The board has input and output connectors and a small circuit for muting the audio signal when the tonearm is not playing a record. The Beogram control system manages the muting relay on this board to occur when the tonearm is lowered and raised. There is a delay circuit on the board to adjust when the relay turns on the audio signal after the tonearm sets down on a record.

I always replace the original muting relay with a new Beolover replacement relay. The electrolytic capacitor for the delay circuit is replaced as well.  I also add a small switch that can connect/disconnect signal ground from system ground. That option allows for Beogram 4002 phono connections to non-B&O preamplifiers to compensate for any grounding differences that can cause hum in the signal.

Here are the before and after photos of the output board restoration.

Before

After

While I had the soldering iron hot I went ahead and replaced the two RPM speed indicator lamps with Beolover LED modules. As mentioned in previous Beogram 400x restorations these two lamps are part of the platter motor circuit and the Beolover LED modules provide some added stability.

There are a couple of electrical tasks in the Beogram 4002 cabinet and the tangential arm assembly (like the reservoir capacitor and the arm position sensor lamp) but I will dive into some of the mechanics of the Beogram 4002 next.