By far the most common problem is an insufficient ground between the TIM6 board and the engine block head. Make sure this is a good tight connection. Sometimes I recommend two ground wires from the board to two different places on the block to make sure. If the board is not properly grounded, high voltage from the coil will back feed into the Hall sensor and will blow it out. It could also blow out the transistors on the board. Ultimately, there should be NO resistance from the spark plug threads on the head to the ground connection of the ignition module.
Problem: LED does not light.
Solution: The LED should light each time the magnet passes under the Hall sensor. The Hall sensor should be no farther than 1/32" from the magnet when the magnet is directly under. Also, the polarity of the magnet is critical. The south pole of the magnet should be facing the Hall sensor. If the distance and polarity is correct, you may need to replace the Hall sensor. Temporarily bypass the Hall sensor by shorting pins 2 and 3 of the Hall sensor. If the LED lights, then the Hall is bad.
Problem: LED blinks, but no spark.
Solution: Disconnect the coil. Connect a voltmeter to the coil connections on the board. Position the magnet so the Hall sensor is activated, and the LED stays on. The output voltage from the board should be roughly 3/4 of the battery voltage, i.e. if you are using a 6 volt battery, then output should be 4.5 to 4.75 volts. If you are not getting any readings, then one or both of the transistors on the board are probably bad. E-mail me if you want replacements. These run roughly $6 for both, including shipping. If you are getting a good reading, then test the coil by checking the resistance of the primary and secondary windings. The resistance should match the coil specifications. If you bought a coil from us, the specs are on our web page.