Lecture
All faults that for one reason or another occur in the PC or affect its operation are caused by errors that can be classified into the following main types:
- errors in the programs;
- erroneous operator actions;
- errors in the storage and transmission devices;
- equipment errors:
The detection of errors in programs consists in the detection by the system of detecting violations of formalized actions on the part of the program, which entail errors in the calculations. Such violations include, for example, addressing invalid or prohibited addresses, the appearance of invalid operation codes, etc., i.e., everything that can be formalized and provided for in the detection system to verify these formal requirements. Obviously, such protection is able to identify only elementary errors in the program, because it is difficult to create a fairly simple error detection system in the logic of solving the problem.
Errors of this kind are more easily detected by the programmers themselves or by the operators who run the program in accordance with the instructions than by the machine.
Erroneous operator actions are difficult to predict. The operator can start the wrong program, not to mention other more “minor” errors — press the wrong button, transfer the wrong control, etc. The whole complexity of the question is that the cause of the operator’s errors is not only so much inattention, how much increased fatigue in the work and its internal state.
Recent studies have clearly shown the need for special attention to the problem of increasing the reliability of the human factor in control systems of varying complexity and purpose. The effectiveness of man-machine systems drops sharply as the operator’s ability to cope with the responsibilities assigned to him decreases. The ability of a human operator to perform their functions in a timely and accurate manner for a given time is influenced by many factors, of which perhaps the most essential is the psychophysical characteristics determining his condition. Therefore, the possibility of eliminating errors on the part of the operator is associated both with the creation of optimal conditions for his work and with the formalization of the operator’s actions, which makes it possible to introduce criteria for evaluating these actions. However, the determination of which part of the operator’s activities can be formalized to detect errors remains an unsolved problem.
Errors in the data to be written to memory and stored eliminated error correction scheme before recording or by restoring information in memory after receiving error signals. To this end, the original information is stored for a certain time to allow the correction of the data obtained, distorted as a result of the appearance of an error. In some machines, the information is stored with excess bits, which facilitate the task of correcting it. There are various codes that are used in computer memory devices.
Errors in the transmission of information via communication channels are similar. errors in storage devices. These errors are corrected in the process of transmission (using special correction codes) or information is restored in memory (usually by the method of retransmission of data received with an error).
If errors occur in the logic circuits of the machine, a restart is performed if the error is single. If the error is repeated or persistent, the system is repaired or reconfigured (excluding the faulty unit while preserving the system’s further operation).
If errors occur in the control circuits themselves , then the operator himself must choose a further mode of operation. However, if there is a need to continue the calculations, he must remember that for this period of time the machine will be unprotected.
Malfunctions of control circuits can be of two types: the appearance of a false error signal and the absence of a signal when an error occurs in a controlled circuit.
Faults of the first type are detected in two ways: by stopping the device in case of an error, after which the state of the monitored circuit is analyzed and concluded, or by running a special test program that diagnoses the signals of the control circuit during its operation.
Malfunctions of the second type of control circuitry are more dangerous than the appearance of false error signals. Therefore, control circuits are either periodically checked using a test program or, if one or another control circuit cannot be covered by such a check, they are duplicated.
Faults in power , cooling or mechanical systems machine devices can cause erroneous results like faults in logic circuits. In this case, the machine must be stopped and the malfunction that has arisen eliminated. Faults in power and cooling systems are detected by means of sensors and monitoring instruments. Faults in the mechanical devices of the machine are more difficult to install, so the main guarantee of their performance is the timely conduct of preventive maintenance and maintenance of these devices in a technically sound condition.
Before troubleshooting, you must perform a series of actions that will localize the source of the error.
POST issues
During the power-on self-test, most often errors occur due to incorrect hardware configuration. If a POST error occurs, check the following:
Hardware issues after boot
Sometimes problems arise after booting the system, and without changing the hardware and software. To eliminate such errors, perform a series of actions.
Software problems
Software (especially the latest) can cause errors. Most often this is due to the incompatibility of software and hardware.
Adapter issues
Problems with adapters most often occur due to improper installation or allocation of resources (interruption, direct memory access channel and I / O addresses). Also, do not forget to install the latest driver for this adapter, which is known to the operating system.
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Diagnostics, maintenance and repair of electronic and radio equipment
Terms: Diagnostics, maintenance and repair of electronic and radio equipment