Maintaining and repairing Antminer T17+ hash boards can be a daunting task, but with the right knowledge and guidance it is possible to keep your hardware running optimally. This guide will provide helpful tips on how to detect problems in the board, as well as how to diagnose, repair and maintain them for optimal performance. We’ll cover topics such as routine tests, chip detection and positioning, soldering techniques, voltage testing of chips and other components, replacing faulty parts or chips when necessary, preparing maintenance records for feedback purposes after repairs are complete and more. Follow this guide carefully to ensure you get the most out of your Antminer T17+.
Preparation and Maintenance Guidelines
It’s essential to take the time to properly prepare and maintain components before, during, and after installation. This includes applying thermal gel for better heat transfer, forming air ducts for better airflow, connecting power supplies in the correct sequence, fixing chips to prevent overheating, and ensuring test fixtures meet production requirements. Additionally, these guidelines should also include instructions on cleaning components with approved solvents such as isopropyl alcohol or distilled water, as well as how to store components away from extreme temperatures and humidity levels safely. Finally, regularly scheduled maintenance checks should be carried out every few months or at least annually to guarantee the proper functioning of all parts within the system.
Preparation Requirements for Repair Platform, Tools, and Equipment
I. Platform Requirements
The necessary requirements for the platform include a workbench for repairing rubber sheets that must be properly grounded. In addition, an anti-static wrist strap and grounding are also required to prevent static electricity from damaging the materials being worked on.
II. Equipment Requirements
Constant temperature soldering iron (350-360℃) with a specific head for small patches such as chip resistors and capacitors
Heat gun and BGA rework station for disassembling and soldering chips and BGA components
Multimeter, soldering steel pin, and shrink tubing for easy measurement (Fluke 15b+ recommended)
Oscilloscope, Agilent recommended
Hash board tester fixture
Low-temperature solder paste (Alpha OM550), flux, water, and anhydrous alcohol for cleaning panel and soldering residues
Thermal conductive paste for chips and heat sinks after maintenance (may vary by model)
Tin-planting steel mesh, ball-planting steel mesh, solder wire, and solder balls (0.4mm diameter recommended) for chip replacement
Plant tin on chip pin and BSM surface before soldering to the hashboard
Mechanic lead-free circuit board cleaner cleans up the flux residue after maintenance.
Thermally conductive gel is used to apply to the chip surface after repair.
Ball-planting steel mesh, desoldering wick, and solder balls (the recommended ball diameter is 0.4mm).
When replacing a new chip, it is necessary to tin the chip pins and then solder them to the hash board. Apply thermally conductive gel evenly on the chip’s surface, then lock the heatsink.
Serial port code scanner.
Serial port adapter board RS232 to TTL adapter board 3.3V.
Self-made short-circuit probe (use the pins for wiring and welding and heat the shrinkable sleeve to prevent short-circuit between the probe and the small heatsink).
V. Common Maintenance Spare Material Requirements
0402 resistor (0R, 10K, 4.7K,)
0402 capacitor (0.1uF, 1uF)
Maintenance Requirements
Maintenance personnel are required to possess a certain level of electronic knowledge, with at least one year of maintenance experience and expertise in soldering technologies such as BGA, QFN, and LGA packages.
After repairing a hash board, it must undergo at least two tests to ensure that it is functioning correctly. If it fails either of these tests, it will be rejected.
When replacing a chip, it is essential to pay close attention to the operation method to avoid any obvious deformations of the PCB board. It is necessary to check for any open or short circuits, or missing parts in the replacement parts and their surroundings.
Before starting any maintenance work, it is important to check the tools and test fixtures, ensuring they are working correctly. It is also necessary to determine the test software parameters for the maintenance station, version of test fixtures, and other relevant details.
After the repair and replacement chip tests, it is essential to perform a full chip check before proceeding to the functional test. The functional test must ensure that the double-sided heat sinks are soldered correctly and that the cooling fan is operating at full speed. It is necessary to form air ducts by putting three hash boards together when using the chassis cooling function. Even for single-sided production tests, the formation of air ducts is crucial.
When measuring signals, it is advisable to use two fans to dissipate heat and maintain full speed. Using a laser tachometer to test the fan speed is recommended.
During the measurement and maintenance of the front and back of the hash board, the steel windshield should be under 21V voltage. It is essential to keep the maintenance table clean and insulated to prevent any short circuits during maintenance.
When replacing a new chip, it is important to apply solder paste on the pins and the BSM surface to ensure that the chip is pre-tinned before soldering to PCBA for maintenance.
Fixtures at the maintenance end should adopt Repair_Mode mode and config configuration files tested in non-scanning mode. After passing the test, the production end should start the production line from the test piece, while the after-sale end should be installed and aged normally (installed at the same level). The test configuration file can be obtained from TE.
Overview of Antminer T17+ Components
T17+ Hashboard Structure
The T17+ hash board is composed of 44 BM1397 chips and 11 voltage domains, with each group consisting of 4 ICs. The BM1397 chip used by T17+ operates at a working voltage of 1.55V and is equipped with an LDO to supply power to VDDIO 1.8V and VDDPLL 0.8V. The T17+ clock is a 25M crystal oscillator that is transmitted in series from the first chip to the 44th chip.
Boost Circuit of S17+ Hashboard
The boost circuit of the S17+ hash board is powered by the power supply, and boosts from 21V to 24.5V.
Signal Direction of T17+ Chip
The CLK (XIN) signal is generated by a Y1 25M crystal oscillator and is transmitted from chip 01 to chip 44. The voltage during operation is 1.6-1.8V. The TX (CI, CO) signal is input from pin 7 (3.3V) of the IO port, transferred to IC U2 through level conversion, and then transmitted from chip 01 to chip 44. The voltage is 0V when the IO line is not inserted, and 1.8V during operation. The RX (RI, RO) signal is transmitted from chip 44 to chip 01, returns to pin 8 of the signal cable terminal via U1, and then returns to the control board. The voltage is 0.3V when the IO line is not inserted, and 1.8V during operation. The BO (BI, BO) signal is transmitted from chip 01 to chip 44, and the measured value is 0V when measured with a multimeter. The RST signal is input from pin 3 of the IO port and is transmitted from chip 01 to chip 44. The voltage is 0V without IO signal or in standby, and 1.8V during operation.
T17+ Hashboard Key Circuit
During maintenance, the 10 signal voltages in front of and behind the chip, including CLK, CO, RI, BO, and RST, as well as the CORE voltage, LDO-1.8V, PLL-0.8V, and 21 to 23V voltage transformation of the booster circuit, should be measured. Each chip has lead-out test points for detection. To perform a test, plug in the IO line and press the fixture test key, and the PIC will start to work. At this time, the normal voltage of each test point should be as follows: CLK (1.6-1.8V), CO (1.6-1.8V), RI (1.6-1.8V), BO (0V during no operation and 0V during operation), and RST (1.8V). If the status and voltage of the test points are abnormal, the fault point should be estimated based on the circuit in front of and behind the test point. Note that the steel windshield of the hash board is 21V, and the maintenance table should be kept clean and insulated during maintenance to avoid short circuits.
Antminer T17+ Structure
The miner consists of three hash boards, one control board, APW9+ power supply, and four cooling fans.
Identifying Common Issues with Hashboards and Troubleshooting Procedures
An abnormal LDO voltage of 1.8V or PLL voltage of 0.8V can cause various issues. For example, on a single board level, the chip reading may appear incomplete, while on a miner level, there may be fewer chips or dropped boards, and chip crosses may occur. It’s worth noting that the LDO of the last three groups is powered by the 23V output of the boost circuit U6, while the other groups are powered by the 21V divided voltage that is converted by the LDO.
If the working voltage (core voltage) of a chip is abnormal, there can be several negative effects. On a single board level, the chip count may appear abnormal, while on a miner level, there may be fewer chips or dropped boards. Checking the PIC soldering and programming is recommended. It’s worth noting that it’s essential to check the MOS of the corresponding group for a short circuit.
If the chip signal pin output is abnormal (BO / RST / CO / RI / CLK), it’s essential to determine the faulty position according to the signal direction. It’s recommended to measure the impedance of the chip to the ground first after power is off, compared to a good board or an adjacent group. If possible, using X-RAY to view the soldering effect of the chip can be helpful for users.
