The computer motherboard is more complex, the fault rate is high, the fault phenomenon is more complex, the distribution is also more dispersed. The introduction is as follows:
(1) A variety of cable short circuit, circuit breaker
A variety of connectors should not be a short circuit, the pass is disconnected; IC chips, resistors, capacitors, transistors, inductors and other components of the pin break, short-circuit, breakdown; wiring, pin and power supply, ground short circuit guide; printing plate line disconnected , short circuit and pad falling off and so on. These are common failures.
(2) DMA controller and auxiliary circuit failure
DMA controller has strong function, high failure rate, auxiliary circuit chip and input signal circuit also easy to fault.
(3) RS-232 serial interface Controller failure
The serial interface controller in the PC is independent and has a combination with other interfaces. Serial interface failure rate is high. The
(4) clock Controller, bus controller failure
Clock Controller, bus controller, bus driver, control command chip, are likely to be faulted.
(5) memory chip RAM failure
The PC has more memory chips, higher utilization rate and higher failure rate of the chip itself. The
(6) Data bus failure
The CPU, memory, I/O device data bus, bus buffer registers/drives, and so on in the motherboard also have varying degrees of failure. The
(7) Address bus Select、read fault
is displayed in the address bus, address latch, and address buffer registers/drives of the CPU routing address on the motherboard. The
(8) Memory control signal and address generation circuit failure
refers to a circuit error in Ras/cas row/column address selection communication number, row/column address delay control signal and row/column address.
(9) individual socket, pin loose contact bad trouble
refers to chips and sockets due to rust, oxidation, elasticity weakened, pin off welding, broken and bad switch contact caused by the fault.
I/O channel slot failure
refers to the failure of a copper sheet in an I/O channel slot to fall off, Flex, break short, pin false weld, remove weld, dust too much, or drop into a foreign body.
(11) A fault caused by a special condition
refers to a failure caused by shock, strong earthquakes, electric shocks, sudden rise in voltage, mismatched load or unreasonable design, and man-made failure due to improper installation, set-up and use. The timer, the counter, the interrupt controller, the parallel interface controller's chip also can produce the breakdown, but the failure rate is generally very low.
(12) Power controller failure
General power output controller current larger, calorific value, if the control chip or integrated block quality is poor or bad heat, failure rate is high. As well as its surrounding power filter capacitor due to long-term work in high-temperature environment, will also be due to the failure of electrolyte drying, resulting in power output ripple increase caused the motherboard work instability.
The above failure is not generated on a single motherboard, in which about 60% of the failure will cause the motherboard to not start the work, 35% of the failure will make the motherboard work is not normal, and the other 5% or so random special failure, performance of the motherboard status is unstable.