Top tray is clean, bottom tray is dirty?

It's a Bosch SHV4313 built-in dishwasher
Have checked the obvious:
salt, rinse aid, cleaned filters, poked out holes in spray arm but all to no avail.
Has anyone any bright ideas?
Thanks
Clive
Clive, April 2007


done
lower spray arm blocked remove and check by running tap through it

teckno, April 2007
link Click here to see other fixes for Bosch.