TMI3252 (TP29RA) Step-Down Power Module Whatsminer CB2 V16 Control Board

TMI3252 (TP29RA) 2 A DC-DC Step-Down Converter – Whatsminer CB2-V16 Control Board

The TMI3252 (silk-screen marking TP29RA) is a 2 A synchronous buck converter in a SOT23-6 package, operating at a fixed 600 kHz constant-on-time (COT) frequency. On the Whatsminer CB2-V16 control board it provides one of the low-voltage rails that powers the Allwinner H3 CPU's I/O domain or peripheral circuitry. When this converter fails, the control board may boot partially then hang, or it may not power on at all — depending on which rail it feeds.

Why the TMI3252 Fails on Mining Control Boards

Control boards in mining environments endure constant thermal cycling and occasional voltage transients from hot-plug events. Over time, the internal MOSFETs in the TMI3252 degrade, causing the output voltage to droop below the CPU's minimum operating level. Symptoms include intermittent network drops, kernel panics visible on the serial console, or a board that boots to the kernel but fails to launch the mining daemon. A quick measurement on the converter's output pad with a multimeter (board powered, no load from hash boards) will confirm whether the rail is present and in spec.

Replacement Procedure

Locate the TMI3252 on the CB2-V16 — it is typically near the main power-input connector. Remove the failed IC with a fine-tip iron or hot air at 300 °C, clean the six pads, and install the replacement observing pin-1 orientation (dot or chamfer). The SOT23-6 pitch is 0.95 mm, making hand soldering straightforward. After replacement, power the board via a bench supply and verify the output rail voltage matches the design target before reconnecting hash boards.

TMI3252 DC Converter Specifications

Related Whatsminer CB2 Control Board Repair Parts

• Whatsminer CB2 V8 H3 Control Board
• Allwinner H3 CPU – Whatsminer Control Board
• H5TQ2G63GFR DDR3 RAM – CB2 V8 Control Board
• STI3472 600 kHz Step-Down – Whatsminer Control Board

Repairing Whatsminer control boards at component level? Contact us at contact@lys-sz.com for IC kits and volume pricing.

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