Antminer L7 fails to read PIC version troubleshooting

The PIC chip in the Antminer L7 hash board facilitates excellent communication and collaboration between the hash board and other components, thereby ensuring the coordinated operation of the entire system. If the PIC chip malfunctions, it may lead to abnormal miner voltage, data transmission, and communication failures, as well as increase the risk of damage to other hardware. This article explains the fault issues and solutions related to the Antminer L7 PIC chip.

I. Failure phenomenon:

When the Antminer L7 miner is running, the log reports "chain_offset 2, chain 2, get_sw_version error!", which means that the chain 2 hash board failed to read the PIC version. Both chain 0 and chain 1 hash boards successfully found the PIC version number, but the chain 2 hash board needs to be troubleshooted.

II. Failure solution:

1. It is recommended to first use the PICKit 3.5 programmer to reprogram the PIC file for the chain 2 hash board with the failure phenomenon.

(1) Connect the programmer to the computer. Insert the black wire of the 6-pin DuPont cable into the triangular mark on the PICKIT programmer, and align the other end's 6-pin connector into the corresponding slots on a functioning L7 hash board. Proceed with the reading and saving operations.

Note: The flashing software needs to be installed in the computer in advance, and confirm that the PIC chip models of the hash board are the same before the reading operation.

(2) Just like in step (1), connect the programmer to another hash board that needs to be written. Open the flashing software on the computer side, import the file that has just been saved. Click the "Program" button. When "Programming complete" appears, it means that the PIC chip programming is successful.

Detailed flashing video tutorial:

2. If the log still indicates a failure to read the PIC version number from the hash board of chain 2 after re-flashing the PIC file, it is recommended to use a multimeter to measure the pins of the PIC chip on the hash board of chain 2. Place the black probe on the negative terminal of the hash board, and sequentially place the red probe on pins 1, 9, 10, and 11 of the PIC chip to check if the output voltage is about 3.3V. Additionally, it is necessary to inspect whether the resistance of the connecting lines between the PIC chip and the IO interface is normal.

3. If the pin and resistance tests of the PIC chip show normal. Then it may be that the performance of the PIC chip itself is poor. It is recommended to replace it with a new PIC16F1704 PIC chip, and then reprogram the PIC file. Finally, use the test fixture to test the single board. If the result is normal, the chip replacement is successful.

Example diagram (for reference only)

Solving the failure problem of the PIC chip can help the hash board of the Antminer L7 work at an appropriate frequency and voltage, enabling efficient cryptocurrency mining.