Table 3-1. Operator troubleshooting - continued
TEST OR INSPECTION
BUTTON SEWING MACHINE
Step 5. Check quality and condition of thread.
Replace thread if damp or defective (para. 2-13c).
Step 6. Check twist of thread.
Thread must be left-twist thread. Replace thread (para. 2-13c) if right-twist thread
is being used.
Step 7. Check thread size.
Use correct size thread.
Step 8. Check looper.
If looper has rough edges or point is bent, notify next higher level of maintenance.
Step 9. Rear thread tension disks out of adjustment.
Do not attempt to adjust rear thread tension disks, notify next higher level of
LAMP DOES NOT LIGHT.
Step 1. Check lamp ON/OFF switch.
Set lamp ON/OFF switch to the ON position.
Step 2. Check that lamp light cord is plugged into input power outlet.
Plug in light cord into power outlet.
Step 3. Check that light bulb is not broken, burned out, or missing.
If light bulb is burned out, missing, or broken, replace light bulb.
Step 4. Unplug light cord from outlet and check cord and plug for frayed or broken insulation and
If defective insulation, wiring, or plug is found, replace lamp assembly (para. 3-12).