Check the hash board for signs of burning, breakage, bubbling, or corrosion of the sockets.
Use a Fluke 15+ multimeter to measure the resistance of the chip and compare it with the resistance of a normal chip. If there is no significant difference, the chip is not faulty.
For a damaged hash board, we can slightly increase the voltage by 0.5-1V after powering on, then rub the chips on the board to make the problematic chip heat up, and then inspect it visually.
When the initial inspection fails to identify the faulty chip, the following five in-depth troubleshooting methods are needed for precise location.
Use an oscilloscope to check if there are signals (waveforms) at the input and output terminals of the suspected faulty chip.
(1) Inspection Content: Focus on checking the input and output of the chip's control signals (clock signals).
(2) Judgment Criteria: If the control signal is input normally but there is no output, the chip is very likely damaged.
(3) Traceability Method: If there is no control signal input, trace back to the preceding chip, checking each stage until the damaged chip is found.
When a chip is suspected of being faulty, do not rush to remove it. We can connect a chip of the same model to the circuit and power it on, observing whether the fault phenomenon improves, thus confirming whether the original chip is damaged.
If short circuits are found in signal lines and ground lines, such as +5V or other pins that should not be connected to multiple chips, the line can be cut and remeasured to determine whether the problem lies with the chip itself or the circuit board wiring. Alternatively, a signal with an incorrect waveform can be borrowed from another chip and soldered onto it to observe if the fault occurs. If the fault is improved, the chip's quality is assessed.
Find a working standard hash board of the same model as a reference and compare the pin waveforms and chip counts on the two hash boards to confirm whether the original chip is damaged.
Use a dedicated test fixture to test the hash board and quickly locate the chip fault.
Before inspecting and repairing the integrated circuit, you must first be familiar with the function of the integrated circuit used, the internal circuit, the main electrical parameters, the role of each pin, the normal voltage of the pin, the waveform, and the working principle of the circuit composed of peripheral components. If the above conditions are met, analysis and inspection will be much easier.
When measuring voltage or testing the waveform with an oscilloscope probe, do not cause a short circuit between the pins of the integrated circuit due to sliding of the test leads or probes. It is best to measure directly connected to the pins on the peripheral printed circuit. Any momentary short circuit can easily damage the integrated circuit. Therefore, you must be more careful when testing flat-package integrated circuits.
It is not allowed to use an electric soldering iron for soldering with electricity. It is best to ground the shell of the soldering iron. Also, be more careful with the MOS circuit. It is safer to use a low voltage circuit iron of 6~8V.
It is sure to be welded firmly when soldering, and the accumulation of solder and pores is likely to cause false soldering. The welding time generally does not exceed 3 seconds. Therefore, the integrated circuit that has been soldered should be carefully checked. It is best to use a Fluke 15b+ multimeter to measure whether there is a short circuit between the pins, confirm no solder adhesion phenomenon, and then turn on the power.
Do not judge that the integrated circuit is easily damaged. Because most of the integrated circuits are directly coupled, once a circuit is abnormal, it may cause multiple voltage changes, and the damage to the integrated circuit may not be caused by these changes. In addition, in some cases, the measured voltage of each pin is different from the normal voltage. When the values match or are close, it may not always mean that the integrated circuit is good because some soft faults will not cause changes in DC voltage.
When measuring the DC voltage of the IC pins, a multimeter with an internal resistance of the meter head greater than 20KΩ/V should be used. Otherwise, there will be a significant measurement error for the voltage of some pins.
The power integrated circuit should have a good heat sink, and it is not allowed to work in a high-power state without a heat sink.
The content of this article is from the Internet, compiled and edited by ZEUS MINING.
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