You can make your own current-limited power supply, probably from bits and pieces you already have. Let’s say that you have a 5v dc power supply and a hand full of rectifier diodes and resistors (various values and sizes).

Put a series chain of forward biased rectifier diodes and resistor(s) across your 6v supply. Choose enough diodes to give you a 3v output. Now choose a combination of series/parallel resistors to give you a 2v drop with a current of, say 100mA. You need 20 ohms - so that could be 5 x 100 ohm resistors in parallel.

The most current that can put out is the full 5v across 20 ohms - but at that point the output voltage will be near zero.

Bench supplies, well reasonable ones, allow you to set a current limit as well as an output voltage. At loads below that current limit - it operates as a constant voltage supply. At loads above - it operates as a “constant current” supply. You would set the output current limit to 100mA and that’s the most that it will output.

Now the rectifier diodes plus resistor would allow the current to increase above 100mA, up to 250mA when the output voltage will be near zero (short circuited) - if you want better than that, then you can add a transistor and a few other components.

That is pretty much exactly a conventional momentary switch. It just happens to be packaged for use controlling something a little different.

It should be fine for your application.

One thing to note - the contacts will probably “bounce” as the switch is closed. Produce a string of momentary connections and disconnections for, oh, say the first few thousandths of a second. That’s perfectly normal for a mechanical switch.

That won’t matter in its intended application. But if you are using it with electronics, say counting the number of times the switch is operated - the results can be unexpected.

You can look up “debounce” to see how this can be worked-around.

Wear trainers not sling backs. Molten solder and your tootsie don’t go well together.
I turn the printed circuit board component side down and wave a hot air gun over the flip side, whilst tapping the board against the edge of work bench. The result is usually a cascade of components (and blobs of molten solder).

Very therapeutic. When I’m stuck trying to work out how to do something, when everything I have tried has failed miserably, I deconstruct something electronic. No, I keep well away from psychiatrists.

You (I anticipate) won’t be doing this 9 hours a day, 7 days a week - most of the nasties are long term exposure ones, so a one-off should be fine. If anything ever irritates your eyes or throat, get out of there and ventilate the place.

You probably have already sussed this - but:

DuPont connectors equates to logic level signals. There may even be a 3.3 v <>5v link selector on the adapter.

Whereas DB9 equates to “RS232” level signals. Generally, at least the capability to accept those voltage levels, even if not necessarily producing them.

My first step tends to be to connect tx to rx and see if characters typed in a terminal/emulator get echoed.

An RS232 breakout box is pretty much a given necessity, when it comes to sorting out what’s happening on all those pins and sorting out what to connect to what.

The standard countryside yokel reply when asked for directions applies, " Arrh, If you need to get to there, I wouldn’t be starting from here".

For battery powered LED lighting - you shouldn’t be using 12v LED strips. You should be using bare LEDs and a constant current supply. Converting cell voltage to 12v, only to use (probably) resistors to limit LED current isn’t the way to go.

You will lose far more, efficiency wise, starting from there, than you are worrying about losing in the series or parallel considerations.

But then, you’d design the required power source and then the charger associated with it - not start with a charger, which then constrains your battery pack topology.

We have a council-supported “man cave” - with a couple of funded workshop technicians and lots of unpaid volunteer specialist engineers, mechanics, DIY’ers etc. Plus a very well equipped multi-discipline workshop. So you could take those bits of kit there and someone would give you a hand setting them up, teaching you how to use them, repairing them/maintaining them as needed. Even getting them calibration certificates (thanks to one of the volunteers who has access to calibration equipment). If you don’t have one locally - wouldn’t the technician at a local school/college/university help? Is there a local community online group that you could join and ask for help?

'fraid that a little bit of effort producing the circuit diagram from the boards is really needed.

I think that it will show what has to be a microcontroller with an input pad going to the switch and another pad going to a base resistor for q1. Q1 switching power to LEDS via RA - D.

The long light looks to be fitted for a an IR receiver. With U1 near it possibly the decoder. As they show the thing stuck on a rafter presumably way out of reach - I suspect that 's a picture from the version with an IR controller. They have produced a cheaper version, without the sensor and re-used the photos.

Now, if that’s how it is - I’d just remove the microcontroller and glue one of my favs upside down on the board and run wires from its pins to the relevant pads (removing the existing microcontroller). I haven’t bought one recently, but 8 pin ones were costing me less than 50p… Having programmed the replacement with an added option to stay on.

If you mean a replacement slide-in US standard module - I fear that your chances are slim. I don’t know of a standard that applies to such plates. As it came with a, presumably, external disc drive - asking that manufacturer or its US agent/distributor for help might get something. Even a free replacement power supply. Worth asking, surely?

I don’t recommend using an inline adapter - unless used vertically, the leverage would be too great, unless you added a third leg… You might look for a right angle adapter - that’s the norm in the UK. They can work out well.

Otherwise, you could get an EU socket strip, replacing the plug on the end of its cable with a US one (if it doesn’t actually come with a US plug already).

Acid etch, followed by electrolytic copper plate, followed by nickel plate.
Sorry, can’t help with sourcing a replacement.

Any particular shunt resistor that you have in mind? You are correct that the lamp brightness would remain the same whilst in the regulated zone. I was more thinking of operation outside that region - eg in a short condition. Having a lamp as the series resistor would reduce the fault current compared to using a fixed resistor.
Not sure what you you mean by “fewer choices of resistance”. The lamp would be the series resistor - other than that, what resistor did you have in mind?