¿Cómo reparar la fuente de
alimentación Antminer APW12?
Antminer APW12 Power Supply Repair Guide
Version date: 2020.4.16
Contents: Mainly describes how to troubleshoot various faults of the power
supply APW12 and how to use testtools for accurate troubleshooting.
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I. Requirements for Maintenance Platform
1. Constant temperature soldering iron, above 80W (soldering temperature
is 300-350℃), pointed soldering iron tip is used to solder small patches
such as resistors and capacitors, etc., knife-type soldering iron tip is used
for replacing plug-in component by welding (welding temperature is 380-
420 ℃).
2. The heat gun is used for chip disassembly and soldering. Be careful not
to heat it for a long time to avoid PCB blistering (welding temperature is
260 ℃±2 ℃).
3. AC controllable power supply voltage regulator (output 200-250V, limit
current 0-20A) is used for APW12 power-on inspection. If it's not available,
operator can also connect a 100W ordinary light bulb to the utility AC live
wire, but shall pay attention to safety.
4. Electronic load (power 3.6KW, suitable voltage 0-50V); if it's not
available, operator can make a power resistance load matching APW12.
5. Fluke 15b+ Multimeter, suction pistol, tweezers, zj0001000001 or V9
1.2 hashboard testers and special power supply test card firmware
(configure an oscilloscope if available).
6. Flux, lead-free solder wire, water for cleaning panel with anhydrous
alcohol; water for cleaning panel is used to clean up the residue and
appearance of the flux after maintenance.
7. Thermally conductive silicone grease (2500) is used to repair the heat
conduction between the MOS and the heat sinks. The thermally conductive
silicone (704 silicone) is used to fix the cover after the original glue of the
PCBA component is damaged after repair.
II. Requirements for Maintenance Operations
1. Maintenance personnel must have certain electronic knowledge, more
than one year of maintenance experience, have a certain understanding on
the working principle of switching power supply, and master the welding
technologies.
2. Before opening the shell and repairing the PCBA board, the
large capacitor must be discharged. After the voltage is measured with a
multimeter (if it's less than 5V, discharge is completed), the welding
operation can be performed! Please pay attention to confirm to avoid
electric shocks.
3. Pay attention to the operation methods when judging circuit components.
After replacing any device, there shall be no obvious deformation of the
PCB board. The soldering of the bonding pad is reliable. Check the
replacement parts and confirm whether there are few open and short
circuits around them.
4. After the replacement of the key components, the main circuit is checked
and measured to have no short circuit and other obvious abnormalities
before the AC voltage test, otherwise there may be a hidden danger of
miner explosion.
5. When AC220V voltage is needed to judge the circuit signal, please pay
attention to operation protection. The following contents: Notes, key
internal slogans
● The qualification of maintenance personnel must meet the specified
requirements.
● The instruments and equipment used for maintenance must meet the
specified requirements.
● The repaired instruments and equipment must be effectively grounded,
and the maintenance environment requirements should meet anti-static
requirements. Of course, it is better to wear an anti-static wrist strap.
● The materials used for maintenance must meet the specified
requirements; in order to ensure the accuracy and traceability of the
materials used for maintenance, the materials used for maintenance must
be the production materials of the corresponding models, and the
requirements for material replacement must be confirmed;
1. In order to prevent possible electric shock hazards, non-professionals are
not allowed to disassemble the shell;
2. The maintenance personnel need to use a special shelling miner to repair
the power adapter, so as not to damage the internal components of the
product;
3. After the product is opened, it is required to discharge the high-voltage
capacitor;
4. Electronic waste generated during product maintenance cannot be
discarded at will;
5. Defective products must be marked on the repair process card and
placed in a partition;
6. The repaired products must be marked to distinguish;
7. The repaired products must be placed in the repaired area and require
systematic testing before they can be put into storage.
III. Principle and Structure of Power Supply
1. Overview of principles
1.1 APW12 is composed of a large board, three 60mm fans and a lower
shell. Normally, two inputs are connected to AC220V. It has two DC output
voltages, respectively including SB, 12V. The main voltage output 12V-15V
is controlled by PIC port and miner communication.
1.2 The performance characteristics and scope of use are described as
follows:
APW12 power supply is a high-efficiency DC power supply designed and
produced by our company. It has two single-phase AC inputs and two DC
outputs:
1) 12V-15V voltage output is adjustable, the maximum current can reach
12V/300A; 15V/240A
2) 12V voltage fixed output; current can reach 15A.
The adjustable voltage output part can meet the use of common DC loads
within 240A current within the adjustable voltage range, especially is
suitable for servers and miners that have strict power requirements; the
12V voltage fixed output part can meet the control board and cooling fan
use.
1.21 Following characteristics:
It has the following characteristics:
♦ 200-240V wide voltage input
♦ There are under-voltage, short-circuit, overload, over-temperature
protection inside, and it can automatically recover after the fault is
removed.
♦ The selection of high-quality components ensures the stability and
reliability of the product through reasonable design, and can work at full
load for a long time in a high temperature environment within 50°C.
♦ Small size and high power density.
1.3 Introduction to the appearance of APW12 power supply
Note: If you need to test the default voltage of 15.2V at boot, please use an
adapter cable to short-circuit the pin EN of the voltage regulator port with
GND.
The following is APW12 shell and output port diagram
● Distribution on the front panel of the power supply: 2 delta-shaped AC
input ports
3 medium-speed fans with a size of 60*60*25mm
● Distribution on the left side of the power supply: 2 PCB-33 copper solder
terminals with adjustable voltage output
One 4Pin signal terminal
One PCIE terminal with 12 V fixed voltage output
● Distribution on the rear panel of the power supply: the heat dissipation,
acting as the fan vents.
● The AC input terminal on the front panel of the power supply is C14 delta-
shaped AC socket which is snap-in type, and the C13 AC input cable of the
corresponding interface is required for use.
● The 4Pin signal terminal is the communication interface between the
external control board and the power supply. SDA/SCL is the I2C protocol,
and the output voltage of the power supply can be adjusted through I2C. EN
is the enable signal of the power supply, and the control board can enable
the power supply through EN, which is effective at low level.
● The adjustable voltage output part adopts 2 copper strip welding
terminals, one copper strip terminal near the air outlet is the output positive
pole, and the other one near the signal terminal is the output negative pole.
The output wire or output copper strip can be fixed by M4 screws on the
terminal. It is convenient and flexible to use.
● The 12V fixed voltage output part adopts PCIE output terminals. The
schematic diagram of the PCIE output terminal is as follows:
1.4 APW12 power supply parameter table:
2. Maintenance ideas and cases of common faults
2.1. Block diagram of power supply basic principle
2.2 Power PCBA board layout
Layout marking instructions:
AC1 ---the first circuit AC input and EMI circuit, - PFC and main switch MOS
circuit, --- 12V auxiliary and VCC circuit.
AC2 ---the second circuit AC input and EMI circuit, --- PFC and main switch
MOS circuit, --- 12V auxiliary and VCC circuit, --12V output port and PIC
communication port
Main drive IC, PIC control chip --- Main output
This figure is an actual picture. There may be small differences between
different product versions, but the principle is similar.
2.21 Schematic diagram of two AC input EMI to PFC circuit, for example, for
AC1 circuit, focus on measuring F1 safety circuit MOV1; for U2 rectifier
bridge, confirm whether Q4, D7, D5, D6 are damaged (the same inspection
method as the other circuit). Note that when the MOS is damaged, the drive
resistance and circuit may be damaged simultaneously and need to be
replaced. During normal operation, it can be judged that the DC voltage
across the large capacitor is 410-420V.
2.22 Two-circuit 12V auxiliary circuit and fan power supply principle:
For VCC 12V circuit, the power supply judges that there is no short circuit
abnormality. After powering on, this circuit needs to work normally to
supply power to other ICs. Measure TEST15/TEST11 (11.98V-12.3V),
TEST7/TEST13 (11.98V- 12.3V), and in case of any abnormal situations,
check D12; D10; U7; D2; T1; etc.
12V auxiliary circuit and fan power supply, 12V output for miner supply
control board and large fan, VBUS1 or VBUS2 voltage 420V, U5 chip 2 pin
high level starting, if there is abnormal check, Q7; R66, R145, F4, R121 —
Q10; R59; U10; check if F3 has any damage.
12V 0UTJ6 output for miner control board, J7, J8, J31 internal fan
For main PWM chip U9 VCC power supply control, pay attention to the front-
end two PFC need to work normally.
2.23 Main control U22 PWM drive circuit, feedback control voltage
regulation and voltage stabilization principle diagram, focusing on
measuring the main IC U22 VCC power supply and drive photocoupling;
resistance and transistor.
2.24 LLC circuit two-circuit main switch MOS and transformer conversion
voltage-reduction synchronous rectification DC filter output circuit, focusing
on testing the main switch MOS Q14, Q15, Q31, Q32, check whether there
is a short circuit phenomenon at the positive and negative pole of the
output rectifier chip MOS, over-current protection circuit T2, T8 transformer,
etc.
2.25 For PIC control circuit, J15 voltage regulation communication port, J16
programming port, check TEST19- GND, TEST18-GND (3.2-3.3V)
2.26 SMD paster A side and plug-in B side device position screen printing
diagram
Figure 1: SMD paster surface position
Figure 2: Plug-in surface position
2.3 Maintenance process
2.31 Check whether the appearance of the power supply is seriously
damaged or deformed, and whether the DC fan and AC outlet are damaged.
2.32 Power on AC220V and check whether the fan is rotating normally. Use
a multimeter to measures and check whether the output voltage of the J6
terminal is 12V (12.1V-12.50).
2.33 Open the shell and check the components and soldering surface for
sparking and scorching (focus on whether D1, D2, D21 and D22 are
damaged, and whether 12V circuit chip capacitors are burning), use a
multimeter to detect whether the AC input F1 fuse is open circuit, check U2
rectifier bridge and PFC MOS Q4; D7; D5; D6 to confirm whether there is
short circuit (the same inspection method as the other circuit), measure the
main switch of PWM circuit MOS Q31; Q32; Q15; Q16 and output chip MOS
Q17; Q18; Q19; Q20; check whether there is a short circuit. If there is a
short circuit, operator needs to check and replace the component position.
Pay attention to the circuit resistance around the bad bit MOS tube; the
transistor may be damaged and need to be replaced.
2.34 Check whether the auxiliary 12V circuit F3, U5; T1; Q5; D8, D9 and
other components have short circuit or open circuit phenomenon and
whether the surrounding components are burned, etc., if necessary, replace
them.
2.35 If there is no abnormality in the above position, the F1 or F2 fuse
circuit is normal, and the DC fan rotates after the two AC circuits are
powered on (if it doesn't rotate, please measure whether the fan socket is
12V; if it rotates normally, the fan shall be replaced normally), the output J6
is under 12V voltage. Measure and check whether there are DC410V-420V
between the two ends of the two PFC large capacitance TEST20-TEST30 or
TEST2-TEST7 measurement points, otherwise check the PFC chip U21 or U1,
check the 7-pin VCC power supply has 12V or judge the material to be
damaged and replace; if there is no abnormality, the PWM needs to be
detected for circuit U9; U10; U24; power supply VCC has a voltage of 12V or
judge that the material is damaged and replaced, and whether the T5 or T7
drive transformer is damaged.
2.36 Other defects need to be further analyzed and judged according to the
skills of the maintenance personnel. After the above inspections are
completed, the main DC output of the single power supply test needs to be
about DC21.3V after short-circuiting the J15 PIN pin 4-5 pins, as shown in
the EN-GND pin. Note that the short circuit error may damage the chip.
Only after the replacement of the defective device is checked and the
welding is correct, the AC220V test can be performed. Note: If other circuits
are checked that the normal large capacitor is 420V, and there is no output
after short-circuiting, it can also be judged that the PIC chip U12 firmware is
reprogrammed or the IC is burned (generally there are fewer defects)
2.4 Available control board V1.2 and APW9 power PIC port connection test
chart. Mark 1 is dedicated card test firmware, 2 is DC voltage debugging
high and low conversion button, 3 is PIC communication port, 4 is control
board letter socket, 5 is 12V power supply; please note that the yellow
indicates positive and black indicates negative. Note: After the general
power supply defective products are repaired, power on and short-circuit
the PIC communication J15 port EN-GND pin, if there is a voltage output of
about 21V as normal, it can be judged as normal and the control board test
is not required (when the PIC microcontroller is broken, or the firmware is
reprogrammed, then a small board test is required), and the corresponding
miner can be directly installed for testing. After the power supply is
repaired, if the current under 12V with a load is 12A and current under the
main voltage DC21V with a load is 170A, it is qualified.
2.5 Simple judgment and maintenance of common faults in mine power
supply.
2.6 After the maintenance test of the whole power supply is normal, it
needs to operate for aging under more than 80% (140AA) of the rated load
for 2 hours, and if it's qualified, it can be used by the customers.
