blocked screws

[David Halliday]

> At 07:13 AM 3/07/99 PDT, Aldo Giovannigiacomo wrote:
>
> >Is there any chemical product that can help to unblock these screws
without
> >damage accidently the near circuitry?
>
> The damage is done when the screwblade slips out and across the surface of
> the screwhead.
> I use a substance that increases the friction between the screw and the
> screwdriver.
> It appears to be a suspension of silicon carbide grit in oil. A mechanic
> told me that
> 'valve grinding paste' might work as well. My stuff is a purely Australian
> product.
> I've actually managed to remove 'security' screws with completely the
wrong
> tools using this.


Another technique is to heat the screwdriver with your soldering iron - put
the blade of the driver into the screw, hold the iron down near the tip of
the blade for 20 seconds and give it a turn.  Sometimes the screws are glued
into position and sometimes they are just corroded a bit.  Either way, the
heat will break the chemical bond or the expansion of the screw will break
the mechanical bond.

Also, the screwdriver should fit exactly - spending about $20 on a couple
good small drivers is a lifetime investment and saves a lot of hassles...