Antminer S19 Teardown | How Do I Fix the Hash Board on an Antminer S19?

Antminer S19 Teardown requires care using the most out of your hash board testers. The hash board tester’s supporting fixture should allow the hash board to dissipate heat and make signal measurement easier. For the first time, update the hash board tester control board FPGA using the Antminer S19 series hash board tester SD card swiping teardown program.

Unzip the file and copy it to an SD card, and then insert the card into the hash board tester card slot. Power on the device for about a minute. When the control board indicator double flashes three times, the update is finished (if it is not updated, it may cause a certain chip to be bad during the test).

Antminer S19 Teardown and Issues that Require Care

1. When changing the chip, pay attention to the procedure. The PCB board shouldn’t be visibly deformed once any accessories have been replaced. Check for open circuit and short circuit problems in the replacement parts and the surrounding components.

2. The maintenance technicians must be experts in BGA, QFN, and LGA package soldering technology and possess specific electronic understanding and more than a year of maintenance experience.

3. The hash board needs to be inspected for accuracy more than twice after repairs before it may pass.

4. Check the functionality of the tools and hash board testers, identify the maintenance station for software parameter testing, check fixture versions, etc.

5. The chip must be tested during the test of repairing and replacing the chip, and after passing, the function test must be carried out. The little heat sink must pass the function test to show that it was properly welded.

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Thermal gel must be applied evenly on the chip’s surface before attaching the huge heat sink, and the cooling fan must be running at maximum power. When using the chassis as a heat sink, two hash boards should be positioned simultaneously to create an air duct.

6. Utilize four fans to help with heat dissipation while measuring the signal; the fans must run at maximum power.

7. The user must first connect the negative copper wire of the power supply, then the positive copper wire of the power supply, and lastly plug in the signal cable in order to turn on the hash board. The order of installation must be reversed when removing. Remove the signal cable first, then the power supply’s positive copper wire, and finally the power supply’s negative copper wire.

If the user disregards this directive, it is relatively simple to destroy R8, R9, U1, and U2 (not all chips can be found). The repaired hash board needs to cool down before testing the pattern since otherwise it can result in PNG testing.

8. To ensure that a replacement chip is pre-attached and subsequently soldered to the PCBA for repair, printing pins and soldering paste are needed.

Create the test SD card in accordance with the specifications, and create the SD card by immediately unzipping the compressed package of the single-sided heat sink inspection chip;

The test SD card will be created in accordance with the specifications, and an SD card must be created for the double-sided heat sink 8-times patter test, as indicated in the image below;

S19 hash board’s operational structure:

The operating voltage of the BM1398 chip used in the S19 hash board is 0.36V; for the 38th, 37th, 36th, 35th, 34th, 33rd, and 32nd groups (7 groups in total), LDO is powered by the 19V output from the boost circuit U9 and outputs 1.8V. The hash board is made up of 76 BM1398 chips, which are divided into 38 groups (domains), each of which is composed of 2 ICs.

The voltage of each domain that has retreated is decreased by 0.36V, and the 30th group – the first group are provided by VDD13.64V through the LDO to produce 1.8V. Figure 4-1 illustrates how the 1.8V output of this domain uses LDO to supply the entire 0.8V;

Circuit for an S19 hash board boost and S19 chip signal trend:

As previously demonstrated, the boost circuit raises the power supply’s output voltage from 14V to 19V.

1) TX (CI, CO) signal flow direction, from IO port 7 pin (3.3V) into IC U2 through level conversion, and then transmitted from chip 01 to chip 76; the voltage is 0V when the IO signal is not inserted, and the voltage is 1.8V during operation;

2) CLK (XIN) signal flow direction, generated by Y1 25M oscillator, transmitting from chip 01 to chip 76; voltage of 0.7V-1.3V; and 2)
3) When the IO signal is not inserted, the voltage is 0.3V, and the voltage will be 1.8V during computation;

2) RX (RI, RO) signal flow direction, from chip 76 to chip 01, return to the signal cable terminal pin 8 through U1, and then return to the control board;

4) The multimeter measurement value for the BO (BI, BO) signal flow direction, from chip 01 to chip 76, is 0V;
5) If no IO signal is inserted and the equipment is in standby, the voltage is 0V, and when computing, the voltage is 1.8V; the RST signal flow is from pin 3 of the IO port to chip 01;

A Complete Miner’s Architecture

As seen above, the key components of the entire miner are the three hash boards, one control board, the APW12 power supply, and the four cooling fans.

Common issues and hash board troubleshooting techniques
Single board test detection chip is 0 (PT1/PT2 stations), phenomenon
Check the power output in the first step by paying attention to the area below that is circled.

Checking the voltage output in the voltage domain is the next step.
Each voltage domain has a voltage of around 0.36V. Typically, if there is a 14V power source, domain voltage is present. Priority is given to determining the output of the hash board’s power supply terminal and if the MOS is shorted out (measure the resistance between pins 1, 4 and 8). Continue checking whether 14V has power supply but no domain voltage.

Checking the PIC circuit is the third step.
If the voltage on the second pin of U3 is roughly 3.3V and there is output, continue troubleshooting. If not, make sure the hash board tester cable is connected properly, that the hash board is in good condition, and that the PIC has to be programmed.

Steps for programming a PIC in a Antminer S19 Teardown

1. Programming a PIC using a hash board.
   Application: 20200101-PIC1704-BM1398-V89.hex
   Get the programming tool here: PICkit3, pin 1 of the PICkit3 cable must be connected to pin 1 of J3 on the PCB, together with pins 1, 2, 3, 4, and 5.

2. Computer programming tools
   Launch MPLABIPE and choose a device. Click power to choose the power supply mode for the PIC16F1704, then click operate.
   First, choose file to locate the.HEX file to be programmed; next, choose connect to establish a regular connection;
   The final step is to select “program” and then “verify” to trigger a verification to show that the programming was successful.

4. Verify that C55 in the boost circuit output test figure 4-9 can measure a voltage of 19V.

5. check the output of each group of LDO 1.8V or PLL 0.8V

6. Check the chip signal output (CLK/CI/RI/BO/RST).

Make reference to the voltage value range that the signal trend describes. The measured value of the next group can be compared with the measurement if there is a significant voltage value deviation during the measurement.

PS: The chip will report 0 if the hash board is not powered or switched off in accordance with the test sequence, leading to the burnout of R8, R9, U1, and U2;

1. Verify that the welding of U5 is normal when the EEPROM NG is presented on the LCD screen of the hash board tester;
2. If the test read temperature is abnormal and the PIC sensor NG is displayed on the LCD screen of the hash board tester, then troubleshoot as follows:
   A) Verify the normality of the welding of PINs 2, 3, and U3 as well as the welding of the four resistors of R24–R27;

B) Verify the normal operation of the temperature-sensitive 3.3V power supply as well as the four temperature senses U4, R28–R30, U6, R31–R33, U7, R34–R36, U8, R37–R39, and the matching resistance welding, which are all placed on the back of the PCB and are all illustrated in Figure 5-14.

3. The little heat sink and the heat-sensitive chip should both be checked for welding quality. It will be difficult for the chip to dissipate heat and the temperature differential will be impacted by the huge heat sink material’s deformation.

4. Observation: The PT1/PT2 stations’ single board detection chip is incomplete.
   a) LCD display ASICNG: If (0), measure the total voltage of the measurement domain and the boost circuit 19V is normal, then short-circuit the RO test point and the 1V8 test point between the first and second chips using the short-circuit probe, and then run the software to locate the chip. If 0 chip is still there at this point after looking at the serial port log,

one of the following scenarios will occur:

a-1) Check the voltages at the 1V8 and 0V8 test points to see if they are 1.8V or 0.8V using a multimeter. If not, it means that either the two ASIC chips in this domain are improperly soldered or the 1.8V or 0.8V LDO circuit is abnormal; the majority of these issues are brought on by short circuits of 0.8V and 1.8V patch filter capacitors (measure the resistance of the patch filter capacitors related to the front and back of the PCBA).

A-3) Use a multimeter to check R8 or R9’s resistance to see if it is within 10 ohms and the measurement doesn’t fluctuate erratically. Replace these two resistors if necessary if not.
a-4) Inspect the first chip’s pins to see if they are properly soldered (it was found in repair that the pins are tinned observing from the side, but the pins are not stained with tin at all when the chip is removed).

b) If only one chip can be located in step a), the first chip and the prior circuit are likely in good condition. The next chips should be checked using a similar procedure. As an illustration, short-circuit the RO test point and the 1V8 test point located between chips 38 and 39.

Inspect the U1 and U2 circuits for anomalies like resistance welding, etc.

If the log can only locate 38 chips, then there is no problem with the first 38 chips. If the log can only locate 0 chips, then examine the 1V8 first; if it is normal, then there is a problem with the chip after 38. Dichotomous investigation should be continued until the issue chip is located.

Assuming there is an issue with the Nth chip, N-1 chips can be located when the 1V8 and RO between the Nth and N-1st chips are short circuited, but the Nth chip itself cannot be located when the 1V8 and RO between the Nth and N+1th chips are short circuited.

c) LCD display ASIC75: (Reporting 75) This indicates that while the hash board can identify 76 chips at 115200 baud rate, it only finds 75 chips at 12M baud rate, with one chip being undetectable at this speed;

Antminer S19 Teardown Repair strategy:

Through the short-circuit probe, short-circuit the 1V8 test point and the RO test point situated between chips 38 and 39 using the dichotomy approach. If the log can discover 38 chips, there is no issue with the first 38 chips. If the log only finds 46 chips after short-circuiting 47 chips, there is no issue with the visual examination because the 47th chip cannot be detected. Usually, the 47th chip needs to be changed;

d) LCD display ASICNG:

In the following two scenarios, a certain chip is fixed:

Test time refers to the period of time between pressing the start test button and the ASICNG: (X) result being displayed on the LCD. In the first scenario, the test time is essentially the same as the good board (typically, the value of X will not vary each time you test).

Users should concentrate on these 6 resistors as they are likely to be the cause of the aberrant resistance welding of the front and rear CLK, CI, and BO of the Xth chip. The low likelihood is caused by X-1, X, and X+1, which means that among the three chips, the following pins experience aberrant chip welding conditions:

The log at this point typically contains the following information (the red number is not 13 depending on which seat the hash board tester is connected to); during the test, assume that the domain voltage of all the fields in front of the abnormal position is almost less than 0.3V and the domain voltage of the back fields. d-2) The second case: the test time is almost twice as long as the good board. This issue is brought on by poor soldering on the chip, which typically affects the 1.8V, 0.8V, RXT, and CLK pins. It is advised to take a direct reading of the domain voltage to identify the problematic domain. The abnormal position can also be found using the 1V8 and RO short-circuit approach described in section a);

5. Phenomenon: Single board Pattern NG, pointing to insufficient response nonce data (PT2 station).
   The significant distinction between the chip’s properties and those of other chips is what leads to PatternNG. Currently, it has been determined that the chip die has to be replaced, therefore do so.

The log information indicates the following replacement rules:

Simply swap out the chip with the lowest response rate for each domain if the chip’s appearance is unharmed. The response rate of four chips asic[36][37][43][75] is poor, as can be observed from one of the test logs, which is shown in the accompanying picture. Replace the one with the lower nonce in 36 as 36 and 37 are in the same domain.

Check that the chip test was successful and that the PT2 function test serial port was not interrupted (long-distance running).
Watch the serial port print log while running the PT2 test as a repair procedure. Use a short-circuit probe to short-circuit RO&1.8V when the serial port begins to run for an extended period of time. The first chip is where the short circuit begins.

The first chip is fine if the serial port ceases long-term operation following the short circuit. Find the chip that is still experiencing a long-term operating failure using this technique after a certain chip has been short-circuited. Typically, a particular chip damage is to blame, so just replace it;

7. A certain chip constantly reports as NG on the PT2 function test even though the PT1 chip test is fine.
   Check the appearance, test the chip capacitor or resistance up front; typically, a chip capacitor, damaged resistor, or anomalous resistance is the cause;

The following issues are brought on by a control board problem.

The miner as a whole is not operational.
1) Verify the normality of the voltages at various voltage output points. If 3.3V is short-circuited, it is possible to first disconnect U8. The CPU can be unplugged for testing if it is still short-circuited. Replace the matching converter IC if there are any other voltage anomalies.
2) Verify the DDR/state CPU’s with regard to welding if the voltage is normal.
3) Attempt an SD card upgrade for the flash software;
The next two procedures must be taken if the control board card recovery miner is to start normally:
a) The power must be shut off and restarted when the card recovery is successful, and the green LED indicator will remain lit;

b) Wait 30 seconds before turning on again (the time course of turning on OTP).
c) OTP (One Time Programmable), a memory type for MCUs, stands for one-time programmable, meaning that once a program has been loaded into an integrated circuit (IC), it cannot be altered or cleared again;

Antminer S19 Teardown Precautions:

(1) The control board won’t be able to access the OTP function if there is a sudden power outage during OTP or if the time is less than 30s. The user needs to change the U1 in order to resolve the issue that the control board cannot start (not networked) (main control IC FBGA of control board). U1 has been replaced and is no longer usable in the 19 series.
(2) The control board U1 cannot be utilized on other series of devices while the OTP function is activated;

2. The entire miner is unable to locate the IP.
   Probably because of aberrant operation, the IP cannot be located. For troubleshooting, refer to the first point.
   Examine the network port, network transformer T1, and CPU for appearance and welding issues.
3. The miner as a whole cannot be improved.
   Examine the network port, network transformer T1, and CPU for appearance and welding issues.
4. The miner as a whole is incapable of reading the hash board or has fewer links.
   A. Verify the status of the cable connection.
   B. Inspect the control board components matching to the chain.
   C. Examine the resistance surrounding the plug-in interface and the wave soldering quality of the plug-in pins.

Antminer S19 Teardown Failure mode of the entire miner

1. The entire mining test
   Common occurrences include the inability to identify IP, odd fan counts, and chain behavior. Follow the monitoring interface and test LOG suggestions for maintenance if there is a problem with the test.
   1) An abnormal fan display needs to be investigated. To begin, we must determine whether the fan is functioning normally and whether the connection to the control board is normal or aberrant.
   2) Less link: This phrase alludes to the fact that one board out of the three is missing. The connection between the hash board and the control board is typically flawed. To see if there is an open circuit, inspect the cable. the connection is stable. The single board PT2 can be tested by the user to see if it can pass the test. If the test is successful, it is essentially known that the control board is the source of the issue. Use the PT2 repair procedure to fix the test if it fails.

3. Abnormal temperature: Typically, this is a result of a high temperature. Our monitoring system limits the PCB temperature to 90 degrees. If the temperature goes beyond 90 degrees, the miner will warn and stop operating normally. The high ambient temperature and unusual fan operation are typically to blame for the miner’s inability to operate properly. Awkward temperatures will also result from aberrant fan functioning.
4. If, after working for some time, there is no hash rate and the mining pool connection is lost, examine the network;

Check the standard miner’s state after Antminer S19 Teardown

5) One hash board’s hash rate is low: To check whether the domain functioning voltage of this board and the NONCE return are normal in this instance, you can log in to the IP with the Putty program. As instructed by the Putty LOG prompt, you can fix it.
6) Putty application: the command tail-f /tmp/nonce.log-NONCE print the voltage print command with tail -f /tmp/adc.log-domain
These are the precise operations:
1. Enter the IP address of the problematic miner in Putty, then click OPEN.

To check the status of the voltage domain and the NONCE response, enter the user name, password, and test command. The user can do measurement and maintenance based on the printed abnormal chip if the NONCE and domain voltage are abnormal.

Other issues that require consideration during Antminer S19 Teardown

Diagram of the maintenance process Routine inspection First, visually examine the hash board that has to be fixed to check for scorching or PCB distortion. Secondly, after the visual inspection is successful, the impedance of each voltage domain can be tested to determine whether there is a short circuit or an open circuit. If the answer is yes, it must be processed first; whether there are obvious burnt marks on the parts, offset parts, missing parts, etc. If found, it must be taken care of right away. Additionally, verify that each domain has a voltage of roughly 0.36V.

After the routine test is successful (the general routine test’s short-circuit test is required to prevent the chip or other materials from being burned when the power is turned on), the chip can be tested using a hash board tester, and the positioning can be decided based on the results of the test.

In accordance with the results of the hash board tester detection, verify the chip test points (CO/NRST/RO/XIN/BI) and voltages such VDD0V8 and VDD1V8 starting from the vicinity of the problematic chip.

Conclusion

Antminer S19 Teardown anomalous failure location can be located through the power supply sequence, and the signal flow indicates that all signals—aside from the RX signal, which is transmitted backwards from chip No. 76 to chip No. 1—are transmitted forward from chip No. 1 to chip No. 76.

The chip needs to be rewelded after finding the flawed chip. The technique involves adding flux (ideally no-clean flux) around the chip and heating the chip pin solder junctions to a dissolved state to cause the chip pins and pads to re-run in and collect the tin, creating the effect of re-tinning. You can just replace the chip if the issue persists after re-soldering.

With more than two passes on the hash board tester test, the restored hash board can be deemed a good product. When replacing parts for the first time, wait for the hash board to cool down before testing it with the tester, passing the test after which you should set the hash board aside to cool down. Once the hash board has cooled off a bit, repeat the test for the second time.