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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...

Saturday, April 18, 2015

Beomaster 8000: Display Repair (I) - Intermittent Display Segments Replaced with SMD LEDs

The Beomaster 8000 that had the flipped Tape inputs, also had some intermittent display segments. It seems there are two stages of display death. First the segments go intermittent. Often they still work once the Beomaster has heated up, but they blink once in a while...not very pretty. So we decided to rebuild the displays with SMD LEDs. First I took the display PCB out:

Then I unsoldered the displays and removed them. It is best to do all at once. That makes it much more straight forward to take them out from the board:


Then I opened them up:

Here is a picture of the frequency display with the original LEDs still on there. They are not encapsulated, and this is the problem. The small bonding wires detach over time, and that causes the blinking and final disconnect of the LEDs. 
This shows the same board after replacing the LEDs with SMD packages:

I did this to all four displays. Now they are running for 24 hrs in my test fixture to make sure that everything is stable:

Tomorrow, I will put them back together and then test them for some more time before putting them back into the Beomaster.








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