Author Topic: Fairy Lights & Battery Acid on the Electronics  (Read 200 times)

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Offline jonovidTopic starter

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Fairy Lights & Battery Acid on the Electronics
« on: January 04, 2025, 10:54:57 pm »
battery operated fairy lights for a childs bedroom. hanging from the ceiling once forgotten about.
the 4 AA cell 6 volt battery pack leaked acid over the pcb see-image.
I made a repair using a 5 volt AC plug pack power supply from an old modem.
replacing everything except the fairy lights and adding a longer cable.
what I would like to know is the original intended purpose of the microcontroller in a simple 2 wire circuit.
other than just a timer. as any flickering of a single circuit cluster light  would not be that pleasant. 
as most Christmas lights use 2 or 3 strings in parallel circuits to get a pleasant twinkling effect.
Hobbyist with a basic knowledge of electronics
 

Offline Swake

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Re: Fairy Lights & Battery Acid on the Electronics
« Reply #1 on: January 05, 2025, 11:07:16 am »
As you mentioned, this thing is just a timer to save some battery capacity. Eventually it can be a dimmer that reduces intensity over time to make it a 'kids sleep lamp'.

After a good clean this might still work. It is a very simple schematic. Rinse it with water and a eventually a mild detergent. You might want to use a mild brush like a toothbrush. Dry it well before powering up. Make sure there is no moisture under the chip. Measure all the traces to check them.

J3Y is probably a S8050 transistor. See pic borrowed from the internet
When it fits stop using the hammer
 


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