God, how I hate the rotten stuff. I've now been caught twice in two weeks
with Sony KSS xxx series lasers. For those who don't know, these lasers (in
common with lots of other makes) are shipped with the laser diode shorted by
a blob of solder across two closely spaced pads on the little pcb that
carries the connector and power pot. You remove this blob once the device is
installed, by just touching your iron tip against it. The solder has always
in the past, just 'flowed' onto the iron tip by surface tension, I guess.
However, all that has changed with lead-free. Because the bloody stuff
'strings', you have to be REALLY careful that a barely visible whisker
hasn't been left across the pads.

If this happens, you're left with a laser that doesn't burn, and hence won't
read discs. The first one last week, was in a Pioneer, and was reasonably
easy to get at, but this morning's one wasted a whole bunch more time,
because the laser was in the depths of a mechanism in a 300 disc 'jukebox'
type player. You can't test without mostly reassembling the mech.

So now, rather than relying on a removal method that just worked, and on
most units could be carried out with the laser in situ and connected, it is
necessary to remove the solder blob with the laser right out so that you can
hold it up to a light to make sure that the gap is completely clear. Which
rather defeats the purpose of having the laser shorted in the first place
....

Arfa