This symptom generally indicates that a small amount of solder paste has dried out in the nozzle. However, this does not mean that the nozzle is clogged! You just need to purge the dried paste.
To do so:
Remove the paste dispenser from the printer.
- Use Alt+R to disable the motors.
Grab a tissue or paper towel for the purged paste and position it under the nozzle.
Manually turn the gear on the solder paste dispenser counter-clockwise to initiate flow, like when you primed the dispenser. If you get some flow, proceed to step 5 - otherwise, your nozzle may be clogged.
- Turn the gear until you get a steady flow of paste from the nozzle. Your goal is to purge the dried paste, so you want a healthy flow rate.
Allow the paste to purge for 30 seconds. If the flow slows down, turn the gear again to maintain a steady flow. You might observe a small color change as the paste goes from light gray to a darker gray.
Turn the gear clockwise to stop the flow.
- Mount the paste dispenser back on the printer, and try again. Repeat steps 1-6 until paste is dispensing properly.
Solder paste drying out can be mitigated by storing the dispenser with the cap on, tip-downwards.