Brother GTX-4 Instruction Manual page 250

(3) Check a result of the resultant nozzle check patterns, and carry out the following procedures.
Existence or nonexistence of a
nozzle that does not eject any
ink-jet droplets
Such a nozzle does not exist that
does not eject any ink-jet droplets
Such a nozzle exists that does not
eject any ink-jet droplets
<IMPORTANT>

Even if the nozzles on the white side have a bit of problem concerning firing, since the white ink is ejected on one same
spot through multiple nozzles, relatively large amount of ink volume will be used, and firing problem of a single nozzle will
not affect the print quality so much. Even in a condition with a problem concerning firing as shown in (a), print is performed
without a problem as shown in (b).
Step 5: Head Replacement
(1) Replace the print head with a new one.
<TIPS>

For details of replacement method of print heads, refer to "9-2-6. Replacement of print head >>P.264".
Exit
Proceed to Step 5.
(a)
250
Recovery action
(b)
Troubleshooting