Mini2440 ESD problems

We're considering Mini2440 for builting into end-user device.
As we're testing it for ESD sustainability, it seems like it isn't fully
protected against ESD.

I'm using ESD imitator device, it discharges 150 pF capacitor, charged to 8
kV, at the tasted device. I'm discharging it to metal shells of Mini2440's
connectors (USB host, USB device, LAN, SD-card) and approx. 1 of 5 times
board hangs off or reboots.

I've also tried to connect all connector shells to ground, but it made no
effect.

Does anybody have the same problem? Do you know how to protect user device
with Mini2440 from ESD?

Has the ESD test device got a brand name and model number?

Yes, but it's of russian origin and I don't think you'll find information
about it in english:
"Элемком" (Elemkom),
"ЭСР-8000К" (ESR-8000K).

OK.  Just wondered if it was home-made.  Is it a calibrated unit?  Are you
able to test other similar bits of equipment and get them to pass?

My only suggestion would be, looking at page 6 of the schematic and the
little Reset block in the bottom right-hand corner, would be to do
something with the nRESET line.  For example, a bypass capacitor of say 1uF
or pull this line up to 3V3 or down to ground with a 1-10K resistor
(depending on the logic level required for the non-reset condition).  

This might help you determine if it is getting in via this part of the
system. 

Good luck!

I'm seeing the same type of problems.  The board even resets during the IEC
61000-4-2 Horizontal Coupling Plane (HCP) test at lower voltage levels, and
this is an indirect (no contact) test.  I'm using a calibrated Keytek
MiniZap.

Has anybody else been able to harden the board for ESD?

I've tried a few modifications with no luck.  My next attempt will be to
replace the reset circuit with the one given in the Samsung reference
design.