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Beolover SyncDrive: DC Platter Motor Replacement for Beogram 4002 and 4004 (Type 551x and 552x)

Late Beogram 4002 and the 4004 (Types 551x and 552x), which have DC platter motors instead of the earlier synchronous AC motors usually suff...

Showing posts with label plate. Show all posts
Showing posts with label plate. Show all posts

Sunday, May 28, 2017

Beogram 4004 (5526): Adjusting a Bent Aluminum Panel Alignment Pin

When I initially received this Beogram 4004 (5526), removing the aluminum panels took me a while. The main panel around the platter was completely jammed in a 'too far forward' position, which prevented its release by sliding the plinth forward (basically the plinth could not be moved far enough to release the panel). Once the panel was finally off (convinced with a bit of 'gentle violence') it became clear what the issue was:
The alignment pin on the left side was bent forward, which forced the panel to seat too far forward, too. These pins go into holes drilled into the bottom of the panels. This shows the corresponding hole:
The dab of white goo at 5 o'clock is a bit of Alene's glue transferred from the pin, which I used to get me an approximate position of the bent pin relative to the hole when the panel was aligned. After bending the pin a few times iteratively and watching where the glue moved I was finally able to get it properly aligned holding the panel in the correct spot:
On to the final adjustments (which require the aluminum panels to be installed properly)...

Wednesday, November 16, 2016

Beomaster 8000: Step Seven - Replacement of the Speaker Switches with Modern Encapsulated Units and Laser Cut Adapter Plates

The final 'standard restoration task' for a Beomaster 8000 is to replace the speaker switches. My own personal statistics are that in about 50% of all Beomaster 8000s these switches will go bad in the near future if they are used regularly, like for headphone listening etc...They are usually corroded on the inside and frequently when a Beomaster is used again after a long period of storage, they break after a few uses and then the outputs are no longer connected to the speaker jacks. This shows the speaker switches flipped out of their 'compartments' for accessing the solder points:

Note the brown PCB-like base plates that hold the contacts...this switch style has long gone out of fashion in favor of fully encapsulated modern designs that are capable of millions of switchings before they need to be replaced. Unfortunately, these modern switches do not have this base board anymore, and hence they do not fit into the compartments under the heatsink cover. I designed laser-cut adapter plates that mimic the original base plates while snugly fitting the footprint of the modern switches:
This shows them after soldering them in:
And situated in their compartments:
All good now in switch land!

Unfortunately, when I gave this Beomaster a subsequent testing of all functions, I realized that the phono jack in the contact box was broken out and also disconnected. Very beo-unlovely! The next post will report about my repair process of these DIN7 jacks.