Step-by-Step Guide: Removing a Fan from All-in-One Mining Machines

To swap a fan on an all-in-one mining machine, you power the unit down, unplug it from mains, open the control-board and power-supply covers, unplug the failed fan from its matching FAN1–FAN4 header, cut the cable ties and loom tape holding its wire, back out the four fan screws, and drop in a like-for-like replacement wired to the same header. The single rule that matters: the fan you pull and the fan you fit must correspond to the same numbered socket. Get the mapping wrong and the firmware reads a dead tachometer on a channel it thinks is live, throws a fan fault, and refuses to hash.

Why fan correspondence matters

An all-in-one machine runs four fans — two pulling cool air in the front, two exhausting hot air out the back. Each fan is a 4-wire unit: +12 V, ground, a PWM control line the control board uses to command speed, and a tachometer line the firmware reads back to confirm the fan is actually spinning. That tach feedback is the whole safety story. When any fan drops below its RPM threshold, the firmware treats it as a cooling failure, trips thermal protection, and shuts the miner down before the hashboards cook. This is deliberate — it is the same protection layer that guards against a blocked intake or a seized bearing.

Because the firmware monitors each channel independently, the fan numbering on the control board maps one-to-one to the fan numbering on the user panel. Replace a fan on the wrong header and you have simultaneously left a real dead channel unmonitored and hung a healthy fan on a socket the panel labels differently. Match the numbers and the protection mechanism keeps working exactly as designed.

• FAN1 and FAN2 — rear (exhaust) fans
• FAN3 and FAN4 — front (intake) fans

Confirm the exact layout on your unit before you cut anything: the socket silkscreen on the control board is the authority, and it aligns with the number printed at each fan position on the outer panel.

Safety before you open it

The fan headers themselves are low-voltage — the DC side of these machines runs in the single- to low-double-digit volt range and is not a shock hazard. The danger lives inside the sealed power-supply shell: the mains input and the primary-side filter capacitors sit at roughly 400–420 V and hold that charge after you pull the cord. Treat the PSU as a closed box.

1. Stop hashing and power the unit off from its interface if you can reach it.
2. Unplug the machine from mains and give the power supply a few minutes to bleed down before you work near it.
3. Do not open, probe, or reach inside the PSU housing. Fan work never requires it.
4. Work on a grounded surface and keep the shell out of standing water — even a hydro unit’s fan wiring should be handled dry.

Tools and parts

• PH2 Phillips screwdriver for the cover and fan screws.
• Flush cutters for the old cable ties.
• Replacement fan — a like-for-like 120 mm unit (the stock size on these machines is the 120×120×38 mm “12038” frame), 12 V, 4-wire, with a connector and pinout that match the header. A 2-wire or 3-wire fan will not report a tachometer signal the firmware can read.
• New cable ties and loom/fabric tape to re-dress the wire the way it came.

Steps to remove the fan

1. Open the covers. Remove the control-board cover and the power-supply cover. For a front fan you can instead pull just the front control baffle and leave the PSU cover in place. Where a cover is held by a round push-button latch, press the button down to release it, then back out the retaining screws and lift the plate off.
2. Unplug the failed fan. Trace the wire from the fan position on the panel to its header on the control board and unplug that connector — and only that one. Note the header number so the replacement goes back to the same socket.
3. Free the wire. Cut the cable tie(s) securing the fan lead and peel back the protective loom tape. Save the routing in your head or a phone photo — you will re-dress it identically.
4. Rear-fan routing. On a rear fan the lead runs underneath the copper power bus-bar that bolts the power supply to the hashboards. You do not need to remove the bus-bar — there is enough clearance to draw the wire out beneath it. Leave the bolted bus-bar alone; unbolting it is a separate, higher-risk job and is unnecessary here.
5. Unbolt the fan. Remove the four screws holding the fan to the chassis and lift it out.

Fitting the replacement

1. Check airflow direction. Air must move front to back. Every case fan has two small arrows moulded into the frame — one for airflow, one for rotation. Orient the new fan so its airflow arrow points the same way the old one did (intake fans blowing in, exhaust fans blowing out). A fan fitted backwards fights the airflow path and will drive temperatures up even though every channel reports “spinning.”
2. Mount and route. Screw the fan in with the four screws, run the lead back along its original path (under the bus-bar for rear fans), re-tape the loom, and secure it with fresh cable ties so it cannot drift into a fan blade.
3. Plug into the matching header. Seat the connector fully onto the same FAN socket it came off. A half-seated connector reads as an intermittent or dead tach.
4. Close up and verify. Refit the covers, reconnect mains, power on, and watch the miner’s status/kernel log. All four fans should report a healthy RPM and no fan-error state, and temperatures should settle into the normal band under load.

Common mistakes

• Wrong header. The number-one cause of a “fixed” fan still throwing a fault — the replacement went onto a different socket than the failed one.
• Reversed airflow. Fan spins, RPM reads fine, temps climb anyway. Check the frame arrow.
• Wrong wire count. A 3-wire fan on a 4-wire header loses PWM speed control or tach feedback, giving erratic behaviour or a persistent error.
• Pinched or loose lead. An unsecured wire can wander into the blades; a cut lead under the bus-bar kills the channel. Re-dress it the way it came.

Warranty note: replacing a fan does not affect the machine’s warranty. If the miner still faults after a correct swap — multiple fan errors, temperatures that never settle, or a fault that follows the header rather than the fan — the problem is upstream on the control board, not the fan, and it’s time to escalate.

Related: Trace a fan or cooling fault before you open the case with the ASIC fault finder, source a matched 12038 fan and connectors from ASIC repair parts, read up on the thermal throttling protection that a dead fan trips, or hand the unit to our bench through start a repair.