Fanuc alarm 913: DRAM PARITY : (BYTE 1)
system alarm · Fanuc 0i-D
What it means
A parity error was detected in the second byte (byte 1) of the dynamic RAM used by the CNC system software while it was executing. Each DRAM byte lane is checked independently, so the byte number tells you which memory bank failed. This is a hard stop: the control halts and the fault almost always lies in the main CPU/mother board DRAM rather than in user data.
Likely causes
- Defective DRAM on the main CPU board (byte 1 bank)
- Marginal +5V/+3.3V logic supply or noise-induced memory upset
- Board-level degradation from heat or age
Triage note: Bytes 0-7 map to successive DRAM banks; 912 (byte 0) is covered in the main system alarm file. On some generations the same family appears as SRAM parity instead - always confirm against the maintenance manual for your series.
Need the part urgently?
Send us alarm 913 with your machine details — typical RFQ turnaround is 24–48h.