formatting link
This cute little First Alert nightlight someone gave me a while back lasted all of 6 hours before it failed. The lamp is a small U-shaped hot cathode fluorescent made of tubing roughly 11mm diameter. R3 was burned beyond recognition but measured around 32K which may or may not be close to its original value and both cathodes in the lamp are open. All resistors are 1/4W except for R2 which appears to be a 1/2W fusible type.D1, D2, C1, and C2 form a half wave bridge voltage doubler. R1 and R5 discharge the capacitors when the unit is unplugged. R2 serves as the ballast, limiting current in the tube, while R3 and R4 provide current to heat the cathodes. Running the tube from DC can't be good for it under the best of circumstances but I would hope these typically last longer than this one did.