3M Scotch-Weld TC Owner's Manual - page 5
Troubleshooting
Problem
Probable Cause
Correction
1. Low or no
No heat
Check to see that 120 VAC service is on. Thermal fuse in the
adhesive flow
thermostat may have blown. Use Repair Kit #9283.
Shutdown procedure was not observed
Allow the applicator to heat up for at least 30 minutes.
Plugged tip
If the applicator was left on overnight, the tip may be plugged.
This may block adhesive flow and cause backmelt.
CAUTION:
Do not force adhesive. Clear the tip with a small nail or paper
clip. Extrude the remaining adhesive stick and one new
adhesive stick to clear the opening.
Backmelt
Remove the clip and feeder from the track of the applicator.
Push the existing adhesive stick into the white sleeve
approximately 3/4’’ with a new adhesive stick. Remove
the new adhesive stick before it melts and look into the white
sleeve. Look for a thin skin of adhesive around the inside of the
white sleeve. Scrape this skin toward the heat block.
CAUTION: Do not damage the white sleeve. Extrude one
adhesive stick to clear the sleeve.
TO AVOID BACKMELT: Observe the Start-Up and Shut-Down
procedures. Do not force adhesive through the applicator.
2. Dripping* Nozzle
Backmelt
Refer to preceding paragraph on backmelt.
Worn Valve Assembly
Replace valve with Repair Kit #9234
Contaminated adhesive
Keep adhesive clean and free of contamination.
*Thermal expansion may cause some dripping during start-up. This is normal.