www.diamondsystems.com
Zeta User Manual Rev 1.0
Page 5
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Important Safe Handling Information
WARNING!
ESD-Sensitive Electronic Equipment
Observe ESD-safe handling procedures when working with this product.
Always use this product in a properly grounded work area and wear
appropriate ESD-preventive clothing and/or accessories.
Always store this product in ESD-protective packaging when not in use.
Safe Handling Precautions
The Zeta baseboard contains a high number of I/O connectors with connection to sensitive electronic
components. This creates many opportunities for accidental damage during handling, installation and
connection to other equipment. The list here describes common causes of failure found on boards returned to
Diamond Systems for repair. This information is provided as a source of advice to help you prevent damaging
your Diamond (or any vendor’s) embedded computer boards.
ESD damage
–
This type of damage is usually almost impossible to detect, because there is no visual sign of
failure or damage. The symptom is that the board eventually simply stops working, because some component
becomes defective. Usually the failure can be identified and the chip can be replaced.
To prevent ESD damage, always follow proper ESD-prevention practices when handling computer boards.
Damage during handling or storage
–
On some boards we have noticed physical damage from mishandling. A
common observation is that a screwdriver slipped while installing the board, causing a gouge in the PCB surface
and cutting signal traces or damaging components.
Another common observation is damaged board corners, indicating the board was dropped. This may or may
not cause damage to the circuitry, depending on what is near the corner. Most of our boards are designed with
at least 25 mils clearance between the board edge and any component pad, and ground / power planes are at
least 20 mils from the edge to avoid possible shorting from this type of damage. However, these design rules are
not sufficient to prevent damage in all situations.
A third cause of failure is when a metal screwdriver tip slips, or a screw drops onto the board while it is powered
on, causing a short between a power pin and a signal pin on a component. This can cause overvoltage / power
supply problems described below. To avoid this type of failure, only perform assembly operations when the
system is powered off.
Sometimes boards are stored in racks with slots that grip the edge of the board. This is a common practice for
board manufacturers. However, our boards are generally very dense, and if the board has components very
close to the board edge, they can be damaged or even knocked off the board when the board tilts back in the
rack. Diamond recommends that all our boards be stored only in individual ESD-safe packaging. If multiple
boards are stored together, they should be contained in bins with dividers between boards. Do not pile boards
on top of each other or cram too many boards into a small location. This can cause damage to connector pins or
fragile components.
Power supply wired backwards
–
Our power supplies and boards are not designed to withstand a reverse power
supply connection. This will destroy each IC that is connected to the power supply (i.e. almost all ICs). In this
case the board will most likely will be unrepairable and must be replaced. A chip destroyed by reverse power or
by excessive power will often have a visible hole on the top or show some deformation on the top surface due
to vaporization inside the package.
Check twice before applying power!
Bent connector pins
–
This type of problem is often only a cosmetic issue and is easily fixed by bending the pins
back to their proper shape one at a time with needle-nose pliers. The most common cause of bent connector
pins is when a PC/104 board is pulled off the stack by rocking it back and forth left to right, from one end of the
connector to the other. As the board is rocked back and forth it pulls out suddenly, and the pins at the end get
bent significantly. The same situation can occur when pulling a ribbon cable off of a pin header. If the pins are
bent too severely, bending them back can cause them to weaken unacceptably or even break, and the
connector must be replaced.
