How to disassemble control board from your ANTMINER S15&T15?

To pull the control board out of an Antminer S15 or T15, you cut all power at the wall, unplug the PSU leads, then free the board by unclipping the signal ribbon that runs to each hashboard, the fan connectors, and the board’s own power lead before backing out the four mounting screws. The whole job is a low-current, signal-side operation — done carefully it needs nothing exotic. What follows is the disciplined version: the exact order, the traps that kill boards, and how to confirm the swap before you seal the unit back up.

What the control board actually does on an S15/T15

The control board is the brain, not the muscle. It runs the mining firmware, holds the network stack (that’s the Ethernet jack, the status LEDs and the reset button you see on the face plate), and talks to each hashboard over a thin signal ribbon. On this generation the board also carries the SD-card header used for firmware recovery. Critically, it does not carry the heavy hashboard current — the ~14.5 V, high-amperage rails run straight from the external PSU into each hashboard on their own connectors. The control board’s job on the power side is only to command the on-board voltage regulator (the hashboard PIC and its DC-DC stage) so each chip domain gets the right voltage. That is why removing it is comparatively safe: you’re pulling signal and low-current leads, not a busbar.

Tools you’ll want

• PH1 (and a PH2) Phillips screwdriver — magnetized helps
• Anti-static wrist strap, clipped to bare chassis metal
• A small parts tray or magnetic mat for screws (they are not all the same length)
• Phone camera — photograph every cable and its orientation before you touch it
• Optional: plastic spudger to release stubborn ribbon latches without stressing the socket

Before you start: safety

Kill power at the wall and unplug the PSU completely. Do not rely on the miner being “off” at the controller — the PSU stays live. The low-voltage DC side (~14.5 V) will not shock you, but it can push enormous current: a dropped screwdriver across a rail will arc and vaporize metal, so keep tools clear until the PSU is unplugged. Never open the PSU shell. The dangerous mains-side capacitors live inside that sealed brick and hold charge after unplugging; nothing in this job requires you to go in there. Let a hot unit cool — the heatsinks and chips run hot enough to burn.

Step-by-step: removing the control board

1. Power down and disconnect the PSU. Switch off, pull the AC cord, then unplug every DC output lead the PSU feeds into the miner. The unit must be completely de-energized before a single cable moves.
2. Ground yourself. Put on the wrist strap and clip it to bare chassis metal. The control board and hashboards are static-sensitive; a discharge you can’t feel can still kill a chip.
3. Open the case. Remove the top-shroud/cover screws and lift the cover clear to expose the internals. Keep these screws separate — cover screws are often a different length from the board screws.
4. Locate the control board. It sits at the front/side of the chassis and is unmistakable: Ethernet port, status LEDs, reset button, and the SD header. Photograph it in place, cables attached, before disturbing anything.
5. Release the hashboard signal ribbons. One thin signal/data ribbon runs from the control board to each of the three hashboards. These connectors are keyed and often latched — release the latch or grip the plastic housing and pull straight out. Never pull on the ribbon itself. Note the orientation of each so it goes back the same way.
6. Unplug the fan connectors. The 4-wire fan leads plug into headers on or beside the control board. Squeeze the retention clip and lift by the connector. If both fans share a routing path, tag which lead is which.
7. Disconnect the board’s own power lead. Release the small power connector feeding the control board itself. It’s low-current, but still pull by the housing, not the wires.
8. Back out the mounting screws. The board is held by (typically four) machine screws into standoffs. Support the board with one hand as the last screw comes out so it doesn’t drop onto a hashboard.
9. Lift the board straight up and out. Ease it off any standoffs without flexing the PCB. Set it on an anti-static surface, component side up.

How to confirm it worked

Reassembly is this list in reverse — but verify before you seal up:

• Every signal ribbon is fully seated and correctly keyed — a half-inserted or reversed ribbon is a common cause of a “dead” or “0 chips found” hashboard after a swap.
• Fan connectors clicked home on the right headers.
• All mounting screws back in the standoffs they came from (mismatched lengths can bottom out or short).
• Reconnect the PSU last. On power-up, the status LEDs should sequence and, after boot, the unit should pull a DHCP lease — find it in your router or with a network scan and open the miner’s web UI.
• In the dashboard, confirm all hashboards enumerate with the expected chip count and are hashing without excessive HW/error counts. If a board reads all-zero chips, power down and reseat that board’s ribbon first.

Common mistakes

• Yanking ribbons by the flex. It tears conductors or lifts the socket pad. Always pull the housing.
• Losing screw positions. Cover, board and hashboard screws differ — a long screw in a short hole cracks a standoff or shorts copper.
• Skipping the ground strap because “it was working fine.” ESD damage is invisible and cumulative.
• Forcing a keyed connector. If it resists, it’s misaligned — check the key, don’t push harder.
• Working on a live unit. The controller being off is not the PSU being off. Unplug it.

When to escalate

If the board won’t enumerate hashboards after a clean reseat, if the Ethernet jack is dark with no LED activity, or if you see burn marks, corroded contacts, or bulged components on the control board, you’re past a simple pull-and-replace. A failed controller can also masquerade as a bad hashboard, so confirm the diagnosis before ordering parts. If you’d rather hand it off, D-Central runs board-level ASIC repair and stocks the replacement controllers and hashboards for this generation.

Related

Pair this with the ASIC fault finder to confirm whether the controller or a hashboard is actually at fault, source a replacement from ASIC repair parts, pull the matching PDF from the miner manuals library, or start a repair and let the bench handle it.