D9D300 Voltage Regulator Chip for Antminer E9 Pro Hashboard

D9D300 Switching Voltage Regulator Chip | U151 Replacement for Antminer E9 Pro Hashboard Repair

The D9D300 is a switching voltage regulator chip sitting at position U151 on the Antminer E9 Pro hashboard. When U151 fails, the local rail it regulates goes out of spec and the chain refuses to scan — typical symptom is a single hashboard reporting bad while the other two run normally, with the failure traced to U151 on diagnostic probing.

Direct drop-in replacement: lift the dead D9D300, install the fresh chip, confirm Vout to spec under load, then re-energise. The E9 Pro's three hashboards each use this same regulator at U151, so keeping a stock of D9D300s on the bench covers any of the three hashboards. Failure tends to be downstream-driven (a shorted load takes the regulator out protecting itself) — always probe for shorts before installing the new chip.

When to Replace the D9D300

• Antminer E9 Pro chain refuses to scan — one hashboard dead, U151 regulator open or shorted.
• Local rail measures out of spec on a hashboard with otherwise-healthy ASIC chips.
• Visible damage on U151 after a power event — burnt or cracked package, replace immediately.
• Hashboard boots intermittently with random chain drops — U151 degraded under thermal stress.
• Adjacent components on the U151 rail also failed — replace the load shorts before swapping U151 or the new chip fails immediately.

D9D300 Voltage Regulator Specifications

FAQ — D9D300 Voltage Regulator

Q: How do I confirm U151 is the failed part vs the ASIC chips it feeds?
A: Diagnostic flow: hashboard tester reports the bad chain → measure the local rail downstream of U151 → if rail is out of spec or shorted to GND, U151 is suspect. Lift U151, re-measure the rail to GND — if the short is gone, U151 died protecting the load. If the short is still there, the failure is downstream and the new U151 will fail immediately if you install it before fixing the short.

Q: Probe U151 in-circuit without lifting it?
A: Yes — DMM in low-ohm mode from VOUT to GND on the regulator pins. Healthy reads finite resistance (the downstream load). Short reads 0Ω (downstream short caused the failure). Open reads OL with no load detected (regulator itself opened). Lift confirms which side the fault is on.

Q: Always check the surrounding power components?
A: Yes — a shorted MOSFET or downstream cap is a common upstream cause of regulator death. Inspect the surrounding components for discolouration, smell, or visible damage before installing the new D9D300. Skipping this step is the most common cause of repeat failure.

Q: Bulk pricing for E9 Pro repair benches?
A: Yes — email contact@lys-sz.com for reel-quantity D9D300 pricing.

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• 4-in-1 Fan Simulator (Antminer S19 series / L7 / D7 / E9 Pro)

Antminer E9 Pro repair benches stocking D9D300 regulators by the reel? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.