Osbourne User Manual V0.21
Page 5
Bent Connector Pins
: This type of problem can be resolved by re-bending the pins to their original shape
using needle-nose pliers.
The most common cause of a bent connector pin is when the board is pulled off a stack by tugging it at angles
from one end of the connector to the other, in an effort to release it off the stack. Tugging the board off the
stack in this manner can bend the pin(s) significantly.
A similar situation can occur when pulling a ribbon cable off a pin header. If the pins are bent too severely,
bending them back can cause them to weaken or break. In this case, the connector must be replaced.
Power Damages
: There are various causes of power-specific damages that can occur while handling the
board. Some common causes such as
–a metal screwdriver tip slipping, or a screw dropping onto the board
while it is powered-up, causes a short between a power pin and a signal pin on a component.
These faults can cause over-voltage/power supply problems besides other causes described below.
To avoid such damages, assembly operations must be performed when the system is powered off.
Power Supply Wired Backwards
: Diamond Systems power supplies and boards are not designed to
withstand a reverse power supply connection. This will destroy almost all ICs connected to the power supply.
In this case, the board will likely be irreparable and must be replaced. A chip destroyed by reverse or excessive
power will often have a visible hole or show some deformation on the surface due to vaporization inside the
package.
Overvoltage on Analog Input
: If a voltage applied to an analog input exceeds the power specification of the
board, the input multiplexer and/or parts behind it can be damaged. Most Diamond Systems boards will
withstand an erroneous connection of up to 36V on the analog inputs, even when the board is powered off,
but not on all boards, and not under all conditions.
Overvoltage on Analog Output
: If an Analog output is accidentally connected to another output signal or a
power supply voltage, the output can be damaged. On most Diamond boards, a short circuit to ground on an
analog output will deter any damage to the board.
Overvoltage on Digital I/O Line
: If a Digital I/O signal is connected to a voltage above the maximum specified
voltage, the digital circuitry can be damaged. The acceptable voltage range, on most Diamond Systems boards
connected to digital I/O signals is 0-5V, with overvoltage protection up to 5.5V (-0.5 to 5.5V). Overvoltage
beyond this limit can damage the circuitry.
Other considerations are Logic Signals, which are typically generated between 12V to 24V.
If a Digital I/O Line of 12V to 24V is connected to a 5V logic chip, the chip will be damaged, and the damage
could extend to other chips in the circuit.
IMPORTANT!
Always check twice before Powering Up!
