Fanuc alarm SV0300: APC ALARM: n-TH AXIS (PULSE CODER BATTERY)
0i-D servo APC alarm · Fanuc 0i-D
What it means
Absolute position detector (serial pulse coder) battery voltage low/dead - machine position lost, requires re-referencing
Likely causes
- pulse coder backup battery dead (>~5yr old)
- battery cable broken
- pulse coder internal failure
Triage note: TRY BATTERY FIRST - 90% of cases; replace battery with power ON to retain position, then manual reference return to reset APZ
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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A02B-0200-K102
Battery Unit (absolute pulse coder, alpha i) · Primary suspect
- View part →
A860-2000-T301
Pulse Coder (alpha iA1000 built-in) · Check if others ruled out
Need the part urgently?
Send us alarm SV0300 with your machine details — typical RFQ turnaround is 24–48h.