I have the fix for the AIO pen and Cubs. It's a bad ground connection caused by the screw cap (male) and base (female) threads. Clean and scrape all corrosion with a eyeglass screwdriver. The hole in the bottom (AIO pen) is as far as I know not a reset button but when you stick something metal in there it either completes the ground or nudges the battery up. Be careful I eventually pierced the battery. It's a temporary fix. Also check your coils, no rebuilds as that may be the problem, bending factory coils even slightly changes ohms. Battery fully charged, 5 blinking lights means bad ground and probably a trashed battery if it only works consistently while plugged in. Unplugging gets you maybe a 3 second draw. The cubis tank is only $4 more typically and lasts far longer. Remember, BAD GROUND. Find it.