Innosilicon T3+ – Temperature Too High

Controlled cooldown. Power off the miner at the PSU switch and leave it untouched for 15 minutes in open air. After the wait, power on and let the miner run for 10 minutes while you watch per-chain temps on the UI. If temps climb back to trip point within this window, you have a reproducible cooling problem — not a transient. Document per-chain numbers at each minute mark; you will need them for Tier 2 diagnostics.

Clean heatsinks and fan blades with compressed air. Take the miner outdoors. Use compressed gas or a shop compressor capped at 90 psi. Spray through the intake grille, across each fan blade, and down into the heatsink fins from the top. Hold each fan blade stationary with a plastic pick while blowing (free-spinning from compressed air damages bearings). Flip the miner and blow backwards through the exhaust to dislodge compacted dust at the base of the fin stack. Expect a visible cloud of dust.

Verify ambient at the intake. Place a trusted thermometer directly in front of the intake grille, 2-5 cm off the surface, let it equilibrate for 5 minutes. Reading must be 30 degrees C or below for healthy operation, ideally 25 or below. If room thermostat says 22 C but intake reads 34 C, you have hot-air recirculation — the miner's own exhaust or another miner's exhaust is being pulled back into the intake. Re-position the miner, add a duct, or separate stacked units.

Check and unblock the exhaust path. The T3+ exhausts out the opposite face from the intake. If exhaust blows against a wall, into a corner, or into another miner's intake, back-pressure drops airflow through the heatsinks even with healthy fans. Maintain at least 30 cm of clearance on the exhaust side and make sure nothing soft (curtains, cardboard, insulation) can be sucked against the intake. Re-observe temps for 15 minutes after correcting geometry.

Firmware revert if recent update precedes the fault. If temps got worse after a firmware update, flash the previous known-good Innosilicon firmware image for your T3+ hardware revision. Innosilicon's firmware repository is sporadically maintained; community-archived copies on Reddit, BitcoinTalk, and Zeus Mining are often the only reliable source in 2026. Back up your pool and worker config first — Innosilicon firmware updates sometimes wipe worker settings silently.

Replace a failed fan. If diagnostics identified a stalled or underspeeding fan, replace it. T3+ chassis fans are 120mm x 38mm high-static-pressure units on 12 V with 4-pin PWM connectors. Source an equivalent (Delta AFC1212DE or similar) rather than a quiet PC fan — the T3+ needs static pressure. Remove the top cover, unplug the faulty fan, remove its 4 mounting screws, install the replacement in the same airflow orientation, and reconnect. Boot and verify RPM on the dashboard.

Reseat hashboard data and power connectors. Oxidation on ribbon or power connectors produces marginal electrical contact that forces higher voltage to hit frequency — and more heat. Power off, unplug at the wall, wait 5 minutes for caps to drain, then disconnect and reconnect every ribbon and power connector on each hashboard. If connectors look dull or discoloured, clean contacts with 99% isopropyl alcohol and a lint-free swab, let dry fully, reassemble. Boot and observe per-chain temps.

Measure PSU voltage under load at the hashboard connector. With the miner running and hashing, use a multimeter to probe the DC bus at the hashboard-side PSU connector. Expected: stable DC rail in the T3+ nominal window (approximately 12 V logic, higher on the mining rail) with minimal sag. If voltage sags 5% or more under full load, the PSU is tired and the hashboards are compensating thermally — the sag is your thermal root cause. Swap in a known-good T3+ PSU. Never substitute an Antminer APW unit — not compatible.

Re-stack the miner in its rack. If the miner lives in a multi-unit rack, confirm it is not sandwiched between units whose exhaust blows into its intake. Add baffles between units if needed. Canadian home miners running through summer: this is the number-one seasonal fault. Winter-happy rack geometry is summer-hostile without airflow separation. Front-to-back airflow discipline is non-negotiable above 25 C ambient. Re-test under load for at least 30 minutes before concluding.

Repaste one or more hashboards. Highest-value advanced fix on a 5+ year old T3+. Power off 30 minutes. Remove the suspect hashboard. Remove heatsink retention hardware (track torque sequence). Lift the heatsink — warm with a hair dryer if paste fights you, never pry. Clean every chip top and heatsink contact with 99% IPA until shiny. Apply a rice-grain dot of Arctic MX-6 per ASIC. Replace crumbled thermal pads with same-thickness pads (1 mm or 1.5 mm — measure). Reseat with original hardware and torque pattern, reinstall, boot. Expect 5-15 C drop per chain.

Replace a failed NTC temperature sensor. If diagnostics isolated a dead sensor, this is a through-the-board SMD repair. You need a hot-air rework station, flux, and a replacement NTC of matching beta value (typically 10 kilo-ohm at 25 C, B = 3950 — but measure the footprint and match the part exactly). De-solder the failed bead, clean pads, drop the new bead in with tweezers and hot air. Easy to cook nearby SMD caps if careless with airflow. If you're not already comfortable with mining hashboard SMD rework, stop — route to Tier 4.

Replace aged PSU electrolytics. If a sagging T3+ PSU is root cause and you have bench capability, the bulk primary electrolytics (typically 400 V, 680 uF or equivalent) can be replaced. Discharge safely first — a 10 kilo-ohm 5 W resistor across the terminals for 5 minutes, then verify zero volts with a meter. Match voltage rating exactly and equal-or-higher capacitance. Extends the life of an otherwise obsolete Innosilicon PSU by years — often the only practical path since new OEM T3+ PSUs are out of production.

Ship to D-Central when DIY routes are exhausted. If thermal imaging showed an isolated chip hot spot, if a sensor reads implausibly at cold boot, if hashboard shows scorch marks near an ASIC position, or if repaste did not move per-chain temp meaningfully — you are in chip-level repair territory. Innosilicon T3 ASICs are a proprietary platform, replacement silicon is scarce, and reflow requires a Mining Hacker test fixture built for the T3 family. Ship the hashboard (not the whole miner) to D-Central's ASIC repair bench. Mark the ticket `Innosilicon T3+ thermal`.

Prevention: establish a cleaning and monitoring schedule. Schedule compressed-air blow-outs every 3 months in clean environments, every 4-6 weeks in dusty ones. Alert on per-chain temp above 75 C sustained, not just on the hard-trip at 85 C — that gives you roughly 2 weeks of warning before shutdowns start. Document firmware version in use so you can roll back if a future build regresses. Plan a repaste every 2-3 years of continuous operation. On any 5+ year old T3+ PSU, budget a cap refresh before cascading faults begin.

Canadian operator special: plan for seasonal extremes. In winter, the T3+ is a 3300 W space heater that pays you back — leverage it. In summer (above 25 C ambient), plan dedicated HVAC, ducted exhaust to outside, or seasonal shutdown. The T3+ thermal envelope is tighter than modern Antminer gear and will trip at ambients that newer miners tolerate. If you run in a Quebec basement with natural cold in February, you are the target customer — just do not carry February geometry into August without intervention.