Patrick Young wrote:
I have a number of broken Sony VPL-S900 LCD projectors.
It appears on these the blue LCD panel is crap and
literally burns out.

Despite the part number being LCX031ALT2 on green
and red and LCX031ALT1 on blue, I've moved an ALT2 panel
into place from another unit.

This is all good and well, works perfectly. The only
problem is convergence.

There is no adjustment in the screw holes and the mounting
plates appear soldered to the prism assembly so I assume
the convergence was done by aligning and soldering at
the factory. Or is there another way? The alignment is
out by around 4.5 pixels at the bottom and around 3
at the top.

Conspiricy theory: Sony knew the ALT1 was crap and also
knew it would survive the warranty period and folk would
come in for repairs later ....



The alignment may well be in the way the panels are made, hence the
different part numbers. If you'd like to verify, try installing a
different green panel and a red panel instead and see which one makes
the convergence change. If the panels are indeed identical then the
convergence is adjusted in software, if there's no service menu then
you'd need a custom alignment rig. Given the cost of a new blue panel is
probably prohibitive you haven't got much to loose, you may be able to
file the holes a bit larger and adjust the panel that way to make it
acceptable.