Brother KE-430HX Service Manual page 221

Error status #20 The thread trimmer does not operate.
Probable causes
6. Malfunction of main PCB.
Error status #21 The tension release does not operate.
Probable causes
1. Malfunction of main PCB
Error status #22 The machine does not stop at the needle up stop position. ("UP" is frequently displayed after sewing)
Probable causes
1. Incorrect adjustment
2. Problem with machine
operation
Check/ repair/ adjust
a. Turn on the power switch and check LD5
(green) on the main PCB.
OK if illuminated.
b. Turn off the power switch, and with connector
P24 (TPM) disconnected from the main PCB,
check the continuity between terminals 1-2
and 3-4 of connector P24 on the main PCB.
OK if  ohms.
c. With connector P24 (TPM) inserted into the
main PCB, turn on the power switch, carry out
sewing and measure the voltage between
terminals 1-2 and 3-4 of connector P24.
OK if voltage is output at sewing end thread
trimming.
4189B
Check/ repair/ adjust
a. With connector P19 (SOL2) disconnected
from the main PCB, check the continuity
between terminals 1-2 of connector P19 on
the main PCB.
OK if  ohms.
b. With main PCB connector P19 (SOL2)
connected, turn on the power and carry out
sewing, and measure the voltage between
terminals 1-2 of connector P19 (SOL2).
OK if there is voltage output momentarily after
sewing stops.
4296B
Check/ repair/ adjust
Adjust while referring to "9-18. Adjusting the main
shaft motor reference position".
motor Refer to steps 1 to 5 in #18.
KE-430HX/KE-430HS, BE-438HX/BE-438HS
14. ELECTRIC MECHANISM
Parts to be replaced
Main PCB assembly
Parts to be replaced
Main PCB assembly
Parts to be replaced
Power supply motor PCB
assembly
Motor 430 assembly
210