VGML AAH6 LDO Chip 1.2V for Antminer KA3 S21 T21 S19j Pro+

VGML AAH6 (AW37030D120STR) 1.2V LDO Chip – Antminer KA3 / S21 / T21 / S19j Pro+ Hashboard Repair

The VGML AAH6 (full part number AW37030D120STR) is a 1.2V low-dropout linear regulator used on the bias rails of Antminer KA3, S21, T21 and S19j Pro+ hashboards. It generates a clean, low-noise 1.2V output from the upstream board rail, feeding analog reference voltages on a chip group. When this LDO fails, the chip series it feeds drops out of the chain — visible as a missing-chip count in the dashboard.

Where the AAH6 Sits on the Hashboard

On KA3 and S21/T21 boards, several VGML AAH6 LDOs are placed near the BM ASIC chip clusters. Each one feeds the analog 1.2V reference for one or two adjacent chip groups. Because they are low-noise LDOs (high PSRR), they keep clock-domain noise off the analog rails — which is what stabilises hash-rate consistency. Failure modes are open output, output stuck near rail, or thermal shutdown after the small SMD package overheats.

Replacement Procedure

Pre-heat the board to 130-150°C with a hot plate or IR preheater. Remove the failed AAH6 with hot air at 320-340°C using a small precision nozzle, taking care not to lift adjacent 0402 passives. Clean the pads with flux and braid. Place the new chip with pin 1 aligned to the silkscreen mark, reflow at 320°C, and verify under magnification. Bench-test the 1.2V rail and the chip count via the controller before reassembly.

VGML AAH6 / AW37030D120STR Specifications

Related Antminer Hashboard LDOs

• DIO7910A12ST5 KAF 1.2V LDO – Antminer S19XP
• TLV75512PDR 1.2V LDO – Antminer S21 Hydro
• NCP114ASN120T1G 1.2V LDO – Antminer S19K Pro
• DIO7910A08ST5 KAD3B 0.8V LDO – S19Kpro / S19XP / S21 / T21

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