Is their laser breaking a common problem?
From what SamIAm has seen with his purchase of "junk" systems off Yahoo Japan, it certainly seems to be a common reason for why they're sold off really cheap.
My purchase of a "working" one from a Japanese eBay dealer also has laser problems, but I've not had the time yet to try SamIAm's fix.
Has nobody attempted to tackle this before?
Not that I know off ... I think that the regular answer given is just to replace the laser.
AFAIK, that seems to be the usual solution in the PCE world, where the problem isn't exactly uncommon, either.
SamIAm's fearless tinkering has given us/me hope of avoiding having to do that replacement on our PC-FXs.