Chip Domain Bypass

Chip domain bypass is a salvage technique that electrically jumpers out a failed voltage domain so the remaining domains on a hashboard can keep hashing. On Antminer boards, chips are grouped into voltage domains, clusters of chips that share a regulated power rail and sit in series within the board's chip string. Because the string is a daisy chain, a single dead chip or a failed regulator in one domain can take the whole chain offline. Bypassing the bad domain restores continuity to the rest of the string.

How the architecture forces the choice

An S9 hashboard, for example, divides 63 chips into 21 voltage domains; an S17 board divides 48 chips into 12 domains of four chips each. The domains are wired in series for power delivery, so the signal and power path must pass through every domain in order. If one domain is irreparable, jumpering across it lets the chain complete and the board returns to service, though it now runs fewer chips.

Trade-offs and limits

Bypass is a compromise, not a true fix. The board loses the hash power of the bypassed chips, the per-domain voltage balance shifts and may need compensation, and an improperly placed jumper can stress neighbouring domains. It is a way to keep a partially damaged board earning when replacement chips or a clean repair are not available, and it is a judgement call best made after a fixture has confirmed the fault is confined to one domain.

This technique depends on correctly identifying the failing domain first. See Test Fixture for locating the faulty domain, and Kernel Log for the chip-count symptoms that prompt a bypass.