This is a follow up to my recent post about the redesigned Beogram Commander remote control board, which now works in both (DC-motor) Beogr...
Monday, February 23, 2015
Beomaster 8000: Replacement of Indicator Light Bulbs with LEDs
Today I finished rebuilding the display PCB of the Beomaster 8000. After fixing the displays, what remained was to replace the incandescent light bulbs of the four indicators with red LEDs. When I did that the last time, I made a short video discussing the procedure. When I removed the old bulbs, the leads of two of them broke off very easily. I saw this before. It seems that these bulbs die mainly by losing their corroded leads at the point where they are fed through the glass, instead of burning out their filament. Here are a few pictures:
Original light bulbs:
LED replacements. One needs to use two LEDs and a 47 Ohm current limiting resistor:
The two indicator sets need mirrored LED setups to fit the bulb solder pads:
After installation and removal of resistors R34/36/38/40 (otherwise the LEDs will faintly glow if they are in off condition - see video for a discussion):
And in action (the clipping LEDs are off...):
And with covers replaced:
On to the power supply...