2430 Super VGA Video Card – 3
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Approximately 20% of the returned cards are problem-free.
These cards, typically, have the wrong jumper settings or the
customer has problems with the software. This causes
frustration for the customer and incurs a testing charge from
Octagon.
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Of the remaining 80% of the cards, 90% of these cards fail due to
customer misuse and accident. Customers often cannot pinpoint
the cause of the misuse.
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Therefore, 72% of the returned cards are damaged through some
type of misuse. Of the remaining 8%, Octagon is unable to
determine the cause of the failure and repairs these cards at no
charge if they are under warranty.
The most common failures on CPU cards are over voltage of the
power supply, static discharge, and damage to the serial and parallel
ports. On expansion cards, the most common failures are static
discharge, over voltage of inputs, over current of outputs, and
misuse of the CMOS circuitry with regards to power supply
sequencing. In the case of the video cards, the most common failure
is to miswire the card to the flat panel display. Miswiring can
damage both the card and an expensive display.
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Multiple component failures - The chance of a random
component failure is very rare since the average MTBF of an
Octagon card is greater than 11 years. In a 7 year study,
Octagon has never found a single case where multiple IC
failures were not caused by misuse or accident. It is very
probable that multiple component failures indicate that they
were user-induced.
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Testing “dead” cards - For a card that is “completely
nonfunctional”, there is a simple test to determine accidental
over voltage, reverse voltage or other “forced” current situations.
Unplug the card from the bus and remove all cables. Using an
ordinary digital ohmmeter on the 2,000 ohm scale, measure the
resistance between power and ground. Record this number.
Reverse the ohmmeter leads and measure the resistance again.
If the ratio of the resistances is 2:1 or greater, fault conditions
most likely have occurred. A common cause is miswiring the
power supply.