How to replace the Avalon 1346 hash board LDO chip LM1085IS-ADJ?

The LM1085IS-ADJ is a voltage regulator chip located on the Avalonminer 1246 and 1346 hash boards. It has a maximum dropout voltage of 1.5V at 3A load current and features a Zener-adjusted bandgap reference, current limit and thermal shutdown. The chip is widely used in communication equipment, solar and battery management systems, industrial control and automation control and other fields.

The LM1085IS-ADJ voltage LDO chip is a key component in the power management of the Avalon 1246 and 1346 hash boards. It adjusts the input voltage to achieve a stable output voltage to ensure the normal operation of the miner. When the LM1085IS-ADJ LDO chip is damaged or short-circuited, it will cause the hash board output voltage to be abnormal; it will cause the ASIC chip and other electronic components to be damaged due to voltage fluctuations, affecting the normal operation of the miner or even shutting down. At this time, we should replace the failed LM1085IS-ADJ chip immediately.

Taking Avalon 1346 as an example, the specific replacement steps for the LM1085IS-ADJ voltage regulator chip are as follows:

1. Disassemble the miner, take out the faulty hash board and place it on the anti-static insulating pad;

2. The LM1085IS-ADJ chip is located next to the positive power terminal of the A1346 hash board, and its location is marked U98. Use circuit board cleaning fluid to clean around the faulty chip and apply an appropriate amount of no-clean flux on its pins;

3. Set the constant temperature heating platform to about 300°C. After reaching the preset temp, move the hash board to the heating platform; when we see that the tin of the chip pins begins to melt, use tweezers to gently clamp the chip and remove it;

4. Align the pin of the new LM1085IS-ADJ LDO chip with the pads, heat until the tin covers the chip pins, and use tweezers to lightly press the chip for a few seconds to avoid false soldering; if the amount of tin on the chip pins is not full enough, if you cannot firmly grasp the chip, you can add an appropriate amount of tin to the chip pins and heat to melt it.

5. After the chip soldering is completed, move the hash board to an anti-static insulating pad to cool while using circuit board cleaner to clean away any remaining tin and flux;

6. Use a multimeter to check whether the chip soldering is qualified; use the Avalon chip test fixture to check whether the board is operating normally;

7. After passing the test, put the hash board into the miner box and power on the miner for testing.

As the competition in the mining market becomes increasingly fierce, the long-term and stable operation of miner is the key to ensuring profitability. Use the new LM1085IS-ADJ chip to replace the failed chip in a timely manner to quickly restore the operation of the Avalon 1246 and 1346 miners, thereby maximizing revenue.