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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, September 14, 2013

Beomaster 8000 Display Repair

Another Beomaster 8000 display repair marathon. I must have soldered about 280 SMD LEDs by now into these displays (it takes about 70 LEDs and this is my fourth display...;-). I basically repeated what I described in: http://beolover.blogspot.com/2012/09/beomaster-8000-display-repair-hopefully.html
Here is a pic of the outcome. I put them into my display test breadboards and ran them at 2V (~0.53 Amp):

All segments are present. It is a good idea to do a mechanical test while the LEDs are out in the open. I give them a pretty good push and pull with a toothpick in all directions to make sure they have good contact. Since there is no solder mask the solder has a tendency to distribute on the pads, and it can be difficult to create a decent solder bump at the contact pads. Inspection with a magnifying glass is also a good idea to make sure they are aligned and centered precisely. If they are not it is difficult to get the bezels back on in a way that they block the light laterally (if the bezels are not set well and there are gaps, then light enters adjacent segments and in a dark room this can be seen...not acceptable for the beolover!). Now I will give them a 'burn in' over night and then mount the covers back on. this Beomaster 8000 is hopefully soon ready for a test in the living room!

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