FNKS8N90K MOSFET in TO-252 Package | N-Channel 90V / 80A Replacement Part for Antminer Hydro APW11 PSU Repair
The FNKS8N90K is an N-channel MOSFET in TO-252 (DPAK) surface-mount package used on the Bitmain Antminer Hydro series APW11 power supplies. Direct replacement when an original device fails — quickly restores full power delivery to the hydro miner and avoids the cost of a complete PSU swap. The TO-252 package geometry matches the original PCB footprint exactly, so the replacement drops straight in without board-level rework beyond the desolder / resolder step.
Rated for 90V drain-source voltage and 80A continuous drain current, the FNKS8N90K sits in the secondary-side switching or output-stage positions on the APW11 board. When this device fails, the PSU loses voltage regulation, trips on overcurrent, or refuses to start altogether. Targeted component-level repair restores the unit at a fraction of the cost of full PSU replacement. SMD mounting requires professional soldering equipment (hot-air station or fine-tip iron with magnification).
When to Replace the FNKS8N90K
APW11 PSU dead at startup — output MOSFET failed open or short, primary controller can't drive the output cleanly.
Overcurrent trip on PSU startup — short across the MOSFET pulling the primary into protection.
Output voltage drift outside the APW11 spec — degraded MOSFET on one phase, pulling regulation off.
Visible burn marks on the device or its surrounding pads — immediate replacement, swap all parallel MOSFETs on the affected leg.
Preventive PSU refurbishment — replace output MOSFETs alongside electrolytics during a complete APW11 rebuild.
FNKS8N90K MOSFET Specifications
Parameter
Specification
Part Number
FNKS8N90K
Component Type
N-Channel power MOSFET
Drain-Source Voltage
90V
Drain Current
80A
Package
TO-252 (DPAK)
Mounting
Surface Mount (SMD)
Application
APW11 power supply repair
Compatibility
Bitmain Antminer Hydro series PSUs (APW11)
Replacement Type
Drop-in OEM equivalent
Condition
Brand New
FAQ — FNKS8N90K MOSFET
Q: How do I confirm the FNKS8N90K is the failed component vs another part on the APW11? A: Diode-test the suspect MOSFET in circuit with a multimeter — a healthy N-channel reads infinite drain-source resistance with the gate at zero. A short across drain-source confirms a dead part. Visual inspection catches the obvious burn cases.
Q: Should I replace all paralleled MOSFETs on the affected leg or just the dead one? A: For best long-term reliability replace all parallel MOSFETs on the affected leg — the surviving parts have absorbed thermal stress from the failure event and have shortened service life. The cost difference is small versus a repeat failure 3-6 months later.
Q: What rework equipment do I need? A: TO-252 / DPAK rework needs hot-air rework or a fine-tip iron with the right tip. Standard equipment for any modern PSU repair bench. Clean the pads carefully before placing the new device.
Q: Bulk pricing for repair shops? A: Yes — email contact@lys-sz.com with your monthly volume. Reel and tray quantities are stocked.
Related products
Repair shops stocking FNKS8N90K MOSFETs by the reel? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.
📦 Shipping & Customs⌄
🇺🇸🇪🇺 USA & European Union (DDP): Orders are delivered DDP. All customs duties, import taxes, and fees are included — no additional charges on delivery.
🌍 Rest of world: Orders ship from China. Depending on your country, local customs authorities may apply import duties or taxes.
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