Beogram 4004 (5526): When Disaster Strikes - Ripped Off Leaf Spring Adjustment Bolt

I made good progress with the restoration of the Beogram 4004 (Type 5526) that I recently received from a customer in California. Until I came to the part where I adjust the floating chassis and align the platter etc...what is usually a tedious, but fairly straight forward process quickly turned sour with this unit, giving me fodder for another post in my 'when disaster strikes' series!...;-):

What happened was that when I tried to adjust the height of the three leaf springs to get the floating chassis level, one of the adjustment bolts ripped off. I thought it was turning a bit difficult, but in this case it turned out that one of the previous owners had epoxied the nuts to the threaded sections of these bolts. Since I usually use a ratchet with a nut to turn these screws, I did not see that I was actually twisting the bolt and not just turning the nut!

This shows the assembly before the disaster struck (luckily I took a picture after straightening out the grossly bent alignment pins for the aluminum cover plates). The bolt in question is behind the pin to the right: 

This is the section that came off:

After removing the leaf spring it looked like this. The bolt had separated at a level flush with the threaded hole in the enclosure bottom. Pretty Beounlovely!!:

At least, after heating the bolt with my solder station blower I was able to get the nut separated from the bolt fragment:

The next step was dealing with the broken off bolt fragment that sat flush in its threads. Such twisted off bolts are dreaded by anyone how deals with mechanical things! It is usually a bit of a mess to deal with such bolts. Since I only have a mini drill press for delicate tasks, I opted for drilling the M4 bolt out in three steps. First I made a mark with a center punch as centered as possible on the bolt surface. Then I used a 2 mm drill to hollow out the bolt. I used some oil to prevent the drill from getting stuck:

The next step was re-drilling the hole with a 3 mm drill:

And then I finally went in with a 4mm bit. This cleaned out all the remnants of the bolt:

Then I Installed a M4-45mm stainless steel flat head bolt with a nut and a washer:

This was possible since the mounting posts for these adjustment bolts are hollowed out and accessible from the bottom of the enclosure. The flat head of the bolt fit perfectly and flush into the hollow:

And this is how it looked with the spring installed again:

Looks like it never happened! Beolovely!

Beogram 4004 (5526): A New Arrival From California - Initial Assessment

I recently received a Beogram 4004 (Type 5526) from a customer in California. It was sent in the original box double boxed, i.e. with a second box around it and some bubble wrap cushioning between the boxes. This is recommended since the styrofoam inserts of the original boxes are pretty hard, which in my opinion does not provide enough cushioning for the rigors of UPS or FedEx Ground shipping.

I extracted the Beogram from the box. It came without the dust cover. This shows the unit on my bench as received:

It has pretty decent aluminum surfaces with only minor dings. The platter has a slight stain in the center. I hope it is just some dirt that can be washed off. The keypad is in pretty good shape with only light finger smudges, a minor scratch and some small other damages:

This Beogram will receive the Beolover Commander remote control system, with will ensure that this keypad will not need to be used anymore once the deck is back in service. The keypad coating unfortunately tends to degrade due to contact with the oils and acids of the skin. The Commander remote allows full control of the deck via an Apple Remote control.

The plinth is almost pristine with very good corners:

After removing the aluminum panels I discovered that all three alignment pins are bent grossly, probably in an attempt to fit the plates. This show one as example:

It will be 'fun' to bend them back into their correct positions. Unfortunately, this can be a lengthy task since one cannot really see how their position is relative to the holes in the panels when adjusting them. Only repeat trial and error finally leads to the correct alignment of the aluminum plates.

The rest of the unit seems original without obvious signs of previous repair attempts:

As usual with the 4004, the transport locks bushings are completely fragmented:

I will replace them with my 3D printed nylon bushings when I remove the floating subchassis to vacuum all the fragments out of the enclosure. This needs to be done, since the bits and pieces of the original bushings can become lodged underneath the floating chassis and impede its motion.

After this visual inspection I plugged the unit in and pressed start. The carriage started moving and correctly found the LP setdown point and the solenoid activated. All good signs! From the DC platter motor came a loud rumbling, however, indicative of dry bearings. This will be corrected when I take the motor apart and infuse its bearings with fresh oil under vacuum.

In summary, this should be a fairly straight forward restoration project. Stay tuned!