Featured Post

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...

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.

No comments:

Post a Comment

Comments and suggestions are welcome!