I guess I was too happy too early with my Beomaster 6000 display repair...While the LEDs survived my 12 hrs stress test under full load, they did not survive putting the apertures and lenses back on...two solder joints failed. I realized that the low temperature soldering paste did not work very well...after watching a few more SMD soldering tutorials by Norman Meir (yes, I am a fan!!) on youtube it became clear to me that I had to re-solder all of them. I doused everything in rosin flux and re-soldered with a fine tip at 340C using standard 60/40 solder (sparingly). It turns out that one needs to put the tip on the pad for about 5 sec to heat the part high enough that the solder actually flows on the contact pads of the LED. I tried not to touch the LEDs directly to avoid damage. This seemed to work fairly nicely. After wiping the board with alcohol it looked like that:
I tested each LED with a toothpick for mechanical stability. They seem to hold quite a bit of force without damage now...I hooked them up again to my connection manifold and turned them on:
We will see tomorrow, if they survived this torture. I must have heated each of them up about 10 times by now...
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