Does anyone here know about circuitry? I'm trying to repair this alarm clock, batteries corroded and damaged some of the wires. The black wire that broke off I'm confident went to the corroded negative battery terminal.There was another white wire (not

Name
Email
Subject	Spoiler Image
Comment
File
Embed
Password	(For file deletion.)

File: 1788144726534-0.jpg (584.55 KB, 1000x1333, Original.jpg)

File: 1788144726534-1.jpg (587.06 KB, 1000x1333, Circles.jpg)

Clock Repair Anonymous 08/31/26 (Mon) 02:52:07 No.2615

Does anyone here know about circuitry? I'm trying to repair this alarm clock, batteries corroded and damaged some of the wires. The black wire that broke off I'm confident went to the corroded negative battery terminal.
There was another white wire (not pictured) that corroded on both sides and fell off. It was definitely connected to the bottom pin of the clock mechanism on one side, but I'm not sure where the other side goes.
Possibility #1: alarm on/off switch (rectangle with 3 connections). This seems like the obvious option based on the wire color. However, there's no visible corrosion on the open connection which is weird considering that the wire itself was severely corroded. I'm also not sure why the clock mechanism would need 2 connections to the alarm on/off switch.
Possibility #2: the corroded negative battery terminal. This terminal was badly corroded so it would explain the wire corrosion. However, the color scheme doesn't match up; every other battery terminal connection uses the standard red/black color scheme.
Possibility #3: The corroded positive battery terminal. Probably the least likely as this terminal was less severely corroded, but not totally throwing it out.
Possibility #4: Into the controller circuit board. This would be consistent with the button wiring (orange and blue). I'm kinda surprised the wire wasn't hotglued in like everything else in the circuit board if that was the case though.

Any ideas?

Anonymous 08/31/26 (Mon) 07:33:23 No.2616

The photos are not particularly great but if you only have a single wire connected to the on/off switch and you have one wire left, that's almost certainly it. For alkaline corrosion, strong vinegar followed with a brush, and a silicon contact cleaner should do the trick. If the battery contact is totally gone / doesn't work, you might have to either replace it (likely salvaging it from a different broken battery-powered object) or manufacture new ones from a non-braided wire soldered to a small plate cutout.

These switches operate on the basis of sending a voltage on one wire and receiving it on the other (or not, duh). So one wire should be somewhere where you can measure some constant voltage (I think it's pretty safe to plug it in as is and measure the voltage with a cheap multimeter, you should have one regardless) and another should go to the alarm switch in the clockwork mechanism. It's even possible that the clockwork mechanism energizes that pin and the blue wire on the switch is the "start the alarm" signal for the logic board.

Anonymous 08/31/26 (Mon) 23:01:10 No.2617

File: 1788217270119.png (35.71 KB, 794x567, Diagram.png)

>>2616
Thanks, I was using baking soda thinking it was acidic residue but they are ALKALINE batteries after all, aren't they?
Here's a diagram of the wiring.
There are currently 2 wires connected to the on/off switch, one in the middle and one on the "on" side. The "off" side has nothing connected.

Anonymous 09/01/26 (Tue) 07:09:05 No.2618

Yeah it's unlikely it's the 3rd switch wire (you use 3 wires on the switch when changing voltages, for example when changing between 120 V and 240 V on an appliance).

Does the clock work without the wire? At this point you shouldn't be able to blow something up. What's the wire's color? Red is almost always +V, black is almost always -V (negative terminal).

I would assume that button to be a snooze / stop button instead, are you sure it's wired right?

Anonymous 09/02/26 (Wed) 03:23:25 No.2619

File: 1788319405020.jpg (479.84 KB, 1000x1333, JerryRigged.jpg)

>>2618
>>2616
>Does the clock work without the wire?
Yeah, that's part of why it took so long to notice that the alarm was broke because the clock itself still runs without issue.
>What's the wire's color?
White unfortunately.
>I would assume that button to be a snooze / stop button instead, are you sure it's wired right?
It's a meme "tsundere" alarm clock so the button is there if you want to play the sound clips without setting the alarm. I have confirmed the button and speaker still work after replacing the red and black wires on the circuit board and taping the wires to batteries.
>These switches operate on the basis of sending a voltage on one wire and receiving it on the other (or not, duh). So one wire should be somewhere where you can measure some constant voltage (I think it's pretty safe to plug it in as is and measure the voltage with a cheap multimeter, you should have one regardless) and another should go to the alarm switch in the clockwork mechanism. It's even possible that the clockwork mechanism energizes that pin and the blue wire on the switch is the "start the alarm" signal for the logic board.
Good idea, I think this has solved the mystery. While I had the batteries hooked up I measured the voltage between the batteries and the 5th pin on the clock mechanism (connects to the on/off switch). Essentially no voltage between the positive end, but it reads around 2.5V between the negative end, and only when the switch is on. So I'd assume the negative end of the battery should be wired to the 6th pin of the clock mechanism, and the clock mechanism acts as a switch that connects the 5th and 6th pins when the alarm triggers.

I'm going to order some new battery contacts since they're cheap and I have to resolder the new wires to the contacts anyways. After that I'll test the alarm to make sure it actually works before reassembling everything.

Thanks again for your help, I don't do much electrical work and don't think of these things.