I’ve got a holiday rotary-lens projector that’s failed (LEDs won’t light; motor spins just fine). Last year it failed on me presumably due to moisture; I opened it, ran a hair dryer heat gun over the partially-disassembled innards, and it worked.
Plugged it in again this year, noticed some more moisture inside, but it ran fine initially. A few hours later, same symptoms as last year. But the hair dryer trick isn’t working. Fully disassembled it, ran the hair dryer over the LED PCB, over the AC/DC converter, same deal.
Looking at the LED PCB, the 5 LEDs are clearly in series. I’d expect the voltage across the +/- leads to be ~15V assuming modern 3V Vf LEDs. My crappy multimeter reports 2.5V.
didnt get the best photo of the thing
slightly better detail of the LED end
Better photos of the innards
My assumption last year was either that …
- Moisture had bridged some contacts, shorting or otherwise impairing the ability of the AC/DC converter to function as intended
- The added heat re-made a bad contact
The motor is 120V AC, so it doesn’t care about the AC/DC converter. I’d say the AC/DC converter is simply dead were it not for the low DC voltage across the output side.
Assuming that hot air fixed it previously, any ideas? Worth messing with for a sub-$20 purchase?