If your ASIC won’t connect to its pool, work the problem from the outside in: confirm the miner has a network path, then that it can resolve DNS and reach the pool’s host and port, and only then suspect the pool config or the hardware. The overwhelming majority of “no pool connection” faults are a bad pool URL, a blocked outbound port, a DNS failure, or a wrong system clock breaking a TLS handshake — not a dead control board. Chase those first before you touch a screwdriver.
What the fault looks like
On the miner’s web dashboard (Miner Status / Pools page) you’ll typically see one or more of:
- Pool status shows
Dead,Disconnected, or a rejected-shares count with zero accepted shares. - Accepted shares stay at 0 even though the hashboards report a hashrate — the chips are hashing but nothing is reaching the pool.
- The log fills with
connect() failed,resolve host failed,Stratum connection interrupted, or repeated reconnect attempts. - The miner hashes for a few minutes, then the pool drops it and it retries in a loop.
Zero accepted shares with a healthy hashrate is the signature of a connectivity problem. Zero hashrate is a hardware problem — that’s a different guide (see /asic-fault-finder/).
What you’ll need
- A laptop on the same LAN segment as the miner.
- The miner’s IP address (from your router’s DHCP table or an IP scanner).
- The exact pool host, port, and worker credentials from your pool’s dashboard — copy them, don’t type from memory.
- A terminal for
ping,nslookup, andtelnet/ncto test reachability.
Diagnostic procedure
- Verify the pool configuration character-by-character. On the miner’s Pools page, check the URL is in the form
stratum+tcp://host:port(orstratum+ssl:///stratum2+tcp://for encrypted or Stratum V2 pools). Common ports are3333for plain Stratum and443or8443for TLS — but use the exact port your pool documents. The worker/user field is the usual culprit: a stray space, a smart-quote pasted from a webpage, the wrong separator (most pools wantaccount.worker, some wantaccount/worker), or a leftover password requirement. Re-enter the fields by hand rather than trusting a paste. - Confirm the miner has an IP and a gateway. If the miner pulled a
169.254.x.xaddress or shows no gateway, it never got a DHCP lease — reseat the Ethernet, try another switch port and cable, and reboot. No LAN, no pool. - Test DNS resolution. From your laptop, run
nslookup pool.example.com. If that fails, the miner can’t resolve the pool name either. Fix the DNS server handed out by DHCP, or set a public resolver (e.g.1.1.1.1) in the miner’s network settings. A DNS outage looks exactly like a dead pool. - Test reachability to the pool host and port. From a machine on the same network run
telnet pool.example.com 3333(ornc -vz pool.example.com 3333). A connection that opens proves the path is clear. A timeout means something between you and the pool is blocking that outbound port — a firewall rule, a captive/guest network, or upstream ISP filtering. Many restricted or hotel/office networks silently drop non-standard high ports like 3333; switching the pool to its TLS endpoint on443often walks straight through because 443 is rarely blocked. - Check the system clock. If you’re on a TLS/SSL pool endpoint and everything above passes but the connection still refuses, look at the miner’s date/time. A badly wrong clock makes the pool’s TLS certificate look expired or not-yet-valid and the handshake fails. Antminers set time over NTP at boot — if outbound NTP is blocked or no gateway was set at boot, the clock drifts. Correct the time (or unblock NTP) and reconnect.
- Fail over to a second pool to isolate the pool itself. Add a known-good backup pool (a different provider entirely) as pool #2. If the miner connects to the backup but not the primary, the fault is the primary pool or your credentials on it — check the pool’s status page and that your worker/account is active. Pools also issue a Stratum
client.reconnectto migrate you to a new server; if the primary is mid-migration it can look “dead” for a while. - Escalate to the control board only after the network is proven clean. The control board is the small single-board computer that runs the miner’s OS and talks to the pool; the hashboards only hash. If the miner can’t get an IP on a known-good port and won’t respond on its own web UI, the board’s network stack or storage may be corrupt. On boards that boot from a microSD/eMMC image, reflash the firmware image (or re-image the SD card) before condemning the hardware — a corrupt filesystem is far more common than a dead NIC. Only swap the control board as a last resort, and note that boards are keyed to a miner generation, so a replacement must match the model family (see /asic-repair-parts/).
Firmware notes
Third-party firmware changes how you point at a pool and which protocols you can use. Stratum V2 — the encrypted, censorship-resistant successor to V1 — is natively supported by BraiinsOS+ (on industrial Antminers) and by AxeOS / ESP-Miner v2.14.0+ (Bitaxe class); other stock and third-party firmwares remain Stratum V1. If you configured a stratum2+tcp:// URL on firmware that only speaks V1, it will never connect — use the pool’s V1 endpoint instead. When flashing custom firmware, re-enter pool credentials from scratch; migrated configs frequently carry over a malformed worker string.
How to confirm it worked
- The Pools page flips from
Dead/DisconnectedtoAlive/Connected. - Accepted shares start climbing and the rejected-share ratio stays low (a few percent is normal; a high reject rate points to difficulty or latency issues, not a dead link).
- Your pool-side dashboard shows the worker online with a reported hashrate that settles near the miner’s nameplate over 10–15 minutes.
- The connection holds through a reboot without dropping back into a reconnect loop.
Safety and common mistakes
- Don’t factory-reset first. The original impulse to “reset to defaults and reconfigure” wipes your network settings too and can strand a miner that was one typo away from working. Fix the config field; reset only after the network path is proven and the config still won’t take.
- Don’t assume “no internet” — a miner can have a working LAN and still be blocked on the one outbound port Stratum needs. Test the port, not just
ping. - Don’t reflash or reseat boards on a live, powered unit. Power down and unplug before touching connectors. The low-voltage DC side won’t shock you, but a slipped tool across a live board carries enough current to arc and destroy components.
- Change one variable at a time and re-check the Pools page, or you won’t know which fix actually worked.
Related
Confirm the fault is network and not hardware with the ASIC fault finder, look up the exact model wiring and defaults in the miner manuals, brush up on the underlying protocol via the Stratum glossary entry, and if a control board really is dead, start a repair with D-Central.
