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Press PRGRM key, select the program in alarm (check alarm display for program name O-number). Review the line that triggered the alarm - look for GOTO statement, M198, M99 Pxxxx, or G65 Pxxxx command and note the target sequence number.

Use the search function in EDIT mode: Press ADDRESS key, input 'N' followed by the sequence number being searched (e.g., N100), then press down cursor. If 'N NOT FOUND' appears on screen, the sequence number does not exist in the program.

Verify sequence number format matches Fanuc requirements: N-word must be N followed by 1-5 digits (depending on parameter 3001 setting for sequence number digits). Check parameter 3001 in SYSTEM > PARAM > TYPE 3001 to confirm maximum digit count.

Correct the program by either adding the missing sequence number at the intended location or modifying the GOTO/P address to reference an existing sequence number. After editing, perform a memory clear reset (press RESET + cycle power if needed) and re-execute.

Always backup program before editing. If program is protected, check parameter 3202#0 (WTP) write protection setting.

Check the machine operator panel for BLOCK SKIP switches (/1, /2, /3, etc. through /9 depending on control model). Note which switches are in the ON position.

In EDIT mode, search for the target sequence number and verify if the line begins with a slash symbol (e.g., '/N100 G00 X0'). The slash indicates this block will be skipped when the corresponding block skip switch is ON.

Check parameter 3404#6 (NSK) - when set to 1, sequence numbers in skipped blocks are ignored during search. Verify setting in SYSTEM > PARAM > TYPE 3404. If NSK=1 and block skip is active, sequence numbers in skipped blocks cannot be found.

Resolution: Either turn OFF the block skip switch corresponding to the skipped block containing the target N-word, or remove the slash from the sequence number line if it should not be conditionally skipped, or change GOTO target to a non-skipped sequence number.

Verify block skip logic is intentional before removing skip symbols - they may be part of production process control.

Check parameter 0000#3 (SEQ) in SYSTEM > PARAM > TYPE 0000. When SEQ=1, sequence number display and search functions are enabled. If SEQ=0, sequence number operations may be restricted. Standard setting is SEQ=1.

Verify parameter 3001 (maximum sequence number digits) in SYSTEM > PARAM > TYPE 3001. If target sequence number has more digits than this parameter allows (e.g., N100000 when 3001=4), the sequence number is invalid. Standard setting is 5 digits maximum.

Changing parameter 3001 requires power cycle and may affect existing programs - consult machine tool builder documentation first.

For macro programs using GOTO, check parameter 6003 (macro program range). If GOTO target is outside the enabled macro program range or in a program not stored in macro memory area, search will fail.

Review program structure: ensure GOTO is searching in the same program level. GOTO cannot jump between main program and subprogram or between different subprograms. Sequence number must exist in the same program context where GOTO is executed.

GOTO commands in Fanuc controls are limited to local program scope - use M98/M99 for subprogram calls instead of GOTO for inter-program branching.