Troubleshooting your Modlite
Use these steps to narrow down the point of failure to a single piece.
1.) If your light flashes 3 times when activated, that indicates the battery is down to 3v and needs to be changed.
2.) Before anything else, make sure the battery you are using is freshly charged an not faulty. If it won't charge or an error is displayed while on the charger, switch to a different battery to make sure the problem isn't tied to the battery.
Other indications of a bad battery are:
A.) Battery lasts less than 20 minutes even when showing fully charged.
B.) Battery takes more than 6 hours to re-charge. (Initial charge can be 6-8 hours due to the batteries shipping in a stable, low charge state)
C.) Battery isn't recognized when inserted into the charger.
D.) Battery charges when installed in the wrong direction (positive button top oriented toward the bottom of the charger).
E.) Battery gets excessively hot or swells when on the charger (discontinue use immediately)
1.) Make sure the small spring on the back of the head isn't collapsed or broken, this can cause connectivity issues.
2.) Make sure the spring is fully screwed in. It is replaceable and screws in and out with a small set of pliers. Sometimes unscrewing it slightly, then re-tightening it solves connectivity issues.
3.) If possible, swap to another body/tail cap/battery combo to see if the problem follows the head, or involves another piece of the light system.
1.) Make sure the threads are clear of debris and slightly lubricated to prevent galling and allow the head and tail cap to be removed and installed as well as fully seated. We recommend Super Lube as a lubricant.
Tail Cap (clicky):
1.) Make sure the tail cap is fully seated and not hung up on galled threads or debris in the threads.
2.) To diagnose a faulty tail cap, remove the tail cap and with a screwdriver, press down on the battery and touch the interior side of the body. This completes the circuit and if the light functions correctly this way, it is indicative of a faulty tail cap.
3.) The tail cap switch unscrews with a pair of needle nose pliers from the inside of the tail cap. Most of the time this won't affect the operation, but making sure it is seated is a good practice.
Tail Cap (Surefire)
1.) To diagnose a faulty tail cap, remove the tail cap and with a screwdriver, press down on the battery and touch the interior side of the body. This completes the circuit and if the light functions correctly this way, it is indicative of a faulty tail cap.
2.) Surefire Tail Caps are known to sometimes back off or come loose during long strings of fire. The best way to mitigate this is to add a small drop of blue Loctite on the threads to prevent movement from the vibration of recoil.
3.) If the UE or DS00 cap is fully seated, but the light flickers when the pigtail to a remote tape switch is wiggled or pressed into the cap, this is indicative of a bad connection between the switch lead and the tail cap. Most of the time this indicates a faulty tail cap, although the tape switch plug can also cause this issue. The best way to test is to try a known good tape switch, or swapping the tail cap to a different one.