 |
July 16, 2022, 07:41:36 AM |
|
The circuit diagrams of Whatsminer's power supplies have been asked before, but there are few such documents on the market. I found an article on zeusbtc on how to repair whatsminer power supply. So I want to share it with you here, if have any questions, please point out to help.
1. Upgrade the power unlock firmware
No voltage output when powered on alone. Connect the control board to the power supply and upgrade the dedicated firmware for the control board. After restarting the test, the power supply will have an average voltage output.
2. Abnormal voltage
Remove the power supply screws first, then take out the circuit board and remove the fan. Use a multimeter to measure whether the positive and negative poles of the output terminal are short-circuited. If there is no short circuit, measure whether there is a voltage input. The input voltage is generally measured on the two pins of the bulk capacitor.
Measure whether the input voltage is around 420V. If only measured about 300V. This indicates that there is no pressure rise in the PFC. For safety, the capacitor needs to be discharged and subsequent step measurements taken.
First, check the control chip circuit for short circuits or poor soldering. VCC supplies power to the control board chip circuit, so check whether the VCC power supply is normal.
Measure whether the diode triode of the VCC circuit is standard. If it doesn't work, it should be replaced. However, after the power-on measurement, the VCC voltage keeps beating, and the VCC circuit does not work. Therefore, since VCC is rectified by multiple diodes and outputs multiple sets of voltages, please discharge the Capacitor after power off. Therefore, it is necessary to measure whether each rectifier diode is working.
After the measurement, if the filter capacitor is short-circuited, it means that there is a problem with the rectifier output. The measurement transistor works. The diodes are on the front side and covered with glue. Need to pry glue replacement, replace with new diodes. Measure after replacement to confirm that there is no short circuit.
Finally, carry out the power-on test to confirm that the output is normal and the fault is eliminated.
3. The fan is running normally, but the output voltage is abnormal
Use the black test lead of the multimeter to ground, and the red test lead to measure the same pin positions of the four driver chips and compare. Usually the value of the same pin of the chip is the same. If the pin position and the ground value are quite different, the IC driver circuit may be short-circuited. If there is no sign of burning on the surface of the chip, it may be that the MOS tube it drives is short-circuited. Remove the heat sink of the MOS tube.
Use the diode gear of the multimeter to measure the 4th pin (control pin) of the MOS tube. Find the shorted MOS tube. The fourth pin of the normal tube is about 0.57V. Switch the multimeter to the resistance gear, and measure the abnormal group of the 4th pin of the MOS tube. If there is more than one damage, it needs to be replaced.
4. Voltage output reduction
If the fan is not working, check that the fan cable is plugged in properly. Or observe whether the fan speed is too fast. The fan is spinning too fast due to high temperature. The power supply is locked to protect itself, so there is no output.
Check the fan drive circuit to see if the temperature sensing wires on the four heat sinks are loose. The fault of the miner is a fan problem or a temperature problem. Check the relevant line. If there is no problem with the temperature control on the heatsink, there may be a problem with the chip program. You may need to reset the firmware.
|
