Original DF1203812B2FN MARTECH Cooling Fan for Antminer L9 S19kPro S21 S19jxp KS5Pro T21
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Martech DF1203812B2FN 120mm 7000RPM Cooling Fan | High-Speed PWM Replacement for Antminer L9 / S19kPro / S21 / S19jxp / KS5 Pro / T21
The Martech DF1203812B2FN is a 120 × 120 × 38mm 12V / 4.5A / 7000RPM cooling fan used as a front and rear fan across most modern Antminer and Iceriver hashboard chassis. Direct replacement when an original fan fails — typical failure modes include bearing wear (manifests as audible whine or wobble), tachometer signal loss, or full stall after 12–24 months of continuous duty in a high-temperature mining environment.
Built with double ball bearings for longer service life under sustained high-RPM operation, and PWM temperature control for accurate speed modulation. The fan ships with two connector options — pick at checkout to match your miner:
- 5557 Square 4-pin (ATX-style) — Antminer L9, S21, S21XP, T21, KS5, KS5 Pro, S19jxp, S19k Pro and similar.
- KF2510 4.2mm 4-pin Linear — Antminer KS3, X5, Z15 Pro, S19XP, S19, S19Pro-A, S19j Pro, S19j Pro+ and similar.
When to Replace the Fan
- Audible whine, wobble or grinding from the fan — bearing degradation, replace before stall.
- Tachometer signal lost in the miner dashboard — fan controller reports no RPM, board may throttle as a safety response.
- Fan stalled / not spinning on power-up — motor or bearing failed, replace immediately.
- Hashboard thermal throttle with the rest of the cooling path healthy — degraded fan delivering less airflow than spec.
- Fleet refurbishment — proactive fan swap on miners approaching 12–18 months of continuous duty.
Martech DF1203812B2FN Fan Specifications
| Feature | Specification |
|---|---|
| Brand | Martech |
| Model | DF1203812B2FN |
| Size | 120 × 120 × 38 mm |
| Voltage | 12 V |
| Current | 4.5 A |
| Speed | 7000 RPM |
| Noise Level | 70 dB |
| Bearing Type | Double ball bearing |
| Control | PWM (4-pin temperature control) |
| Connector Options | 5557 Square 4p ATX or KF2510 4.2mm 4p Linear (select variant) |
| Packaging | 40 pieces / carton (530 × 300 × 290 mm) |
FAQ — Martech 7000RPM Fan
Q: How do I know which connector variant to order?
A: Pull the existing fan and inspect the harness. Square (ATX-style 4-pin Molex) = 5557. Linear (4 pins in a row, smaller pitch) = KF2510. The variant is also model-specific — modern S21 / KS5 generation = square; S19 / KS3 / Z15 Pro generation = linear.
Q: Is the fan louder than the OEM original?
A: Roughly equivalent — 7000RPM at 70dB matches the typical OEM spec for these miners under full load. PWM control lowers RPM and noise when the hashboards run cooler.
Q: How many fans does a typical Antminer S21 use?
A: 4 fans (2 front + 2 rear). Order the count that matches your fleet's expected refresh cycle.
Q: Bulk pricing for farm operators?
A: Yes — email contact@lys-sz.com with your typical fan replacement volume. Carton-quantity pricing (40 pcs) is the standard tier for farm-level buyers.
Related products
- Martech 12V 5A 7000RPM 14cm Fan – Antminer S21 Pro
- Delta PFM1412DE-SP02 Antminer S21 Fan
- Antminer S19k Pro Cooling Fan 12cm Square 4-pin
- W12E12BS11B5-07 Antminer S21 / S19k Fan 12cm 4-pin Square
Farm operators stocking Martech 7000RPM fans by the carton? Email contact@lys-sz.com for bulk pricing. Worldwide shipping from our Shenzhen warehouse.
Buying in bulk for a mining farm or repair shop?
Get dedicated B2B pricing on this part and across our full catalog — quote response within 24 hours, payment by T/T USD bank wire, and DDP delivery available for US & EU customers (and other lanes on request).
