"Manky Badger" <you.must@be.joking> wrote in message 
news:Saudnf7JU8-PKjLYnZ2dnUVZ8sqjnZ2d@giganews.com...
> 
> "Francisco Sandoval" <fsandoval7@mchsi.com> wrote in message
> news:yIArh.310063$FQ1.73677@attbi_s71...
> 
> > IBTW, the instrument doesn't have a maintenance contract
> 
> I do :o)
> 
> I shall ask our local engineer......

Who says.......

Trace the line back to find out EXACTLY what bit is blocked then flush that 
bit with hot water - NOT bleach.

HTH