PicoBT PT3 Test Fixture Guide: Indexing Broken ASIC Chips on Antminer & WhatsMiner
ASICREPAIR.in Technical Team
TL;DR
The PicoBT PT3 diagnostic fixture indexes broken ASIC chips by sending 50MHz clock and command signals to pin headers, displaying the exact chip index where signal return drops.
PicoBT PT3 Test Fixture Guide: Indexing Broken ASIC Chips on Antminer & WhatsMiner
⚠️ Quick Summary: The PicoBT PT3 diagnostic test fixture is an essential tool for ASIC hashboard technicians. It communicates directly with the PIC microcontroller and ASIC chip chain (BM1397, BM1366, KF1968) to index broken chips, measure EEPROM status, and test CLK/RI signal return.
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🛠️ Required Setup & Cable Connections
| Connector / Header | Target Hashboard Pinout | Function / Signal | | :--- | :--- | :--- | | 18-Pin Data Ribbon | Antminer Control Connector | Transmits CLK, CO, RI, RO data signals | | 14-Pin Data Ribbon | WhatsMiner Control Connector | Transmits SPI / UART communication data | | DC Power Cable | Hashboard Power Terminals | Supplies 12.0V to 15.0V DC from bench PSU | | USB Type-C | Technician PC / OLED Display | Outputs serial debug log at 115200 baud |
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🔬 Reading PicoBT Test Output Logs
When running an Antminer S19j Pro hashboard test, observe the serial output:
``` [PicoBT PT3 v2.4] Initializing Hashboard Test... [Power] DC Rail Voltage: 14.2V OK [PIC] PIC16F1704 Firmware: Recognized (v1.0.4) [EEPROM] AT24C02 Read OK (SN: S19jPro-HB76-00421) [ASIC] Sending CLK 50MHz... Baud 115200 [ASIC] Response: Found 42 ASIC Chips (BM1397) [ERROR] Chain Break at Chip #42! RI Signal = 0.0V ```
This diagnostic log identifies that Chip #42 is failing to pass the RI signal to Chip #43. You only need to inspect or replace Chip #42 instead of guessing across all 76 chips.
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📐 Step-by-Step Diagnostic Workflow
Step 1: Flashing EEPROM Data
If the fixture reports `[EEPROM] Read Error`, flash the correct bin file for the target model using the PicoBT GUI software before testing the chip chain.Step 2: Signal Pin Measurement at the Break Point
1. Locate Chip #42 on the PCB schematic. 2. Measure VDD_IO (1.8V) at the LDO feeding Chip #42. 3. Measure RI signal (Pin 4) and CLK signal (Pin 1) using an oscilloscope or Fluke multimeter.---
❓ Frequently Asked Questions
What does baud rate 115200 mean in PicoBT logs?
Baud rate 115200 is the standard serial communication speed between the PicoBT fixture micro-controller and your PC debug terminal.Can PicoBT PT3 test both Antminer and WhatsMiner hashboards?
Yes. The PicoBT PT3 supports software profiles for Antminer S9/S17/S19/S21/T19/T21 and WhatsMiner M20/M30/M50 series.---
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