Beogram 4004 (5526): Installation of New Transport Lock Bushings

When taking out the main PCB for restoration it is a great moment to also repair the transport lock bushings in Beogram 4002/4004 turntables if they need replacing. The 4004 that I am currently restoring had the orange bushing type that usually is degraded at this point in time. This is the typical look when they start to go:

A closer look after removing the top plate of the lock:

It is a great idea to take the sub-chassis out to clean out all of the fragments. They can be lodged under the sub-chassis impeding its free motion during record play, which negates the vibration insulation afforded by the leaf spring mechanism. Luckily, it is fairly easy to take the entire chassis out in the 4004 since it is only connected by wire-to-board connectors. So after removal of the three transport lock top plates it can be lifted out:

A typical 'find' underneath it:

This shows the chassis solo:

Once it is out it is easy to remove the bushing fragments:

and insert the Beolover replacement bushings, which are available via the Beolover Shapeways store (two parts are needed per bushing since they are designed as two parts which insert from below and from the top):

first the bottom part is inserted:

and then completed with the top part:

After doing this for all three locks it was time to put the chassis back in:

This shows one of the bushings after reassembling the locks:

On to the electronics!