Thanks Huy,

I felt vacuum at multiple points you mentioned. They seem to have weaker
vacuum than before. The shaft is clear though.

On Fri, Dec 10, 2010 at 4:24 PM, Huy  wrote:

> Put some grease onto the back of the adaptor that is used to spin smaller
> substrate then put the adaptor onto the substrate holder, place the wafer
ontop
> of the adaptor then turn on the vacuum to see if you can defeat the vacuum
> interlock. If adaptor is not exist, remove the substrate holder to the point
> that you can put your thumb onto shaft that connecting the substrate holder
and
> the vacuum inlet then turn on the vacuum button (there's an elbow joint @ the
> bottom of the shaft that the substrate holder's connected to, this is where
the
> resist tend to accumulate) ..... remove the vacuum line, fill the shaft with
> liquid, if liquid comes out of the vacuum inlet then you got no blockage.
>
> huy