You can start, with the thing disconnected from the mains, by checking parts for shorted circuits. A failed varister will do that. They are used to protect from an over voltage spike, but then they sometimes stay stuck in the conduction mode. Or you may have a failed switching transistor in the supply.
But really, you can check out the light part with a variable voltage supply and learn just exactly what voltage and current it needs.

Again, novice here...I’m not sure why it would help to apply a variable supply (don’t have one) to see what the light exactly needs—after all the box says output is 12-24 volts and 16hundred-odd mA...doesn’t that tell me? Maybe a lower voltage would continue through up to a point until the bad area rears its head, whereas now hitting it with full mains power brings it to an abrupt halt?
I’ve had good luck in the past at fixing things by the seat-of-my-pants, but usually the problem areas have been it DC fields. When I replaced the two parts the other day, my shakiness was already bad (age) but made worse by the small area to try and get test leads in without creating a short and scaring the bageezus out of me!

 

Knowing the actual voltage that the light requires instead of the capabilities of that power supply would allow you to find a replacement or solve the problem of why the supply fails. That is why.

 

Yep...99 Times out of 100, but there is that 1 chance...lol...

Well, only 98 more fuses to go.

 

Well, only 98 more fuses to go.

Naw...I usually quit somewhere around 2 or 3–I finally quit living “on the edge”...LOL

 

Knowing the actual voltage that the light requires instead of the capabilities of that power supply would allow you to find a replacement or solve the problem of why the supply fails. That is why.

Finding a replacement isn’t an issue—I’ve found one for about 30 bucks. But the light itself wasn’t but 32 dollars, (don’t think they’re in business anymore) and I could easily just replace it with a different model. But what fun would that be? My methods may be “jackleg” but I’ve had good success with them over the years, and a feeling of accomplishment, as well as keeping items from the trash that continue to work for a reasonable amount of time. I just finished reconditioning my laundry washer that is at least 15 years old. It was making noise like a bearing, so off I went into it. Even better, today we have YouTube videos from others that want to help us, and I found one that though it wasn’t exact, it was close enough to help me save some frustration on “how does this damned thing come apart?”
(Thank goodness for the one video that happened to mention the fluid in the balancing ring—I was about to drill some holes to try and drain...) A good feeling when it was back together and running smoothly now...

 

As you say that the power supply says 12 - 24 volts it is probably a constant current output power supply which will drive LEDs with the specified constant current provided the voltage across the LEDs with that current is between 12 and 24 volts. If you use a constant voltage power supply you will need to use a series resistor to limit the current to the required value.

Les.

 

You'll have a little research to do but try THIS diode as a constant current controller. (click on the bold "this")

 

You can buy a new supply for under 3 dollars
It's constant current from the plate you posted it going to put out 1670 mA at somewhere around 23.75 volts
so get you a 50 watt lying one from ebay that's 1500 mA at 24 volts
Led's last longer we had a bunch of $1500 led lights water made the supply shut down

 

One more time: Once you know the voltage and the resulting current draw at that voltage you will be able to use a constant VOLTAGE supply and a single resistor to run the light. The big benefit is that constant voltage supplies are much more common, and usually much less expensive. In addition you would be learning something.

 

One more time: Once you know the voltage and the resulting current draw at that voltage you will be able to use a constant VOLTAGE supply and a single resistor to run the light. The big benefit is that constant voltage supplies are much more common, and usually much less expensive. In addition you would be learning something.

Oh! I see now—VOLTAGE, I was missing that part of the “constant”.

 

The difference between constant current supplies and constant voltage supplies is that with a constant voltage, your current will vary depending on the load. However, it's converse with a constant current supply. If your supply was 1670 mA then whatever the load, the supply will vary the voltage.

For example: Suppose you have a load of 100 ohms (and I'm just picking numbers at random for an example). At 10 volts your load will draw 0.1 amps (100 mA). Suppose you want 100 mA. If your load can vary (it happens), suppose the load wants to act like a 90 ohm load, then a constant current (CC) supply will vary the voltage. The voltage will drop to 9 volts. At 9 volts a 90 ohm load will draw 100 mA. Suppose the load presented is only 50 ohms. The voltage will fall to 5 volts. 5V ÷ 50Ω = 0.1 A (100 mA).

The reason you might want a CC supply is because sometimes a load can be added to a circuit. I have a CC supply on my under cabinet lighting. I can run a single puck light or I can daisy-chain additional puck lights, up to six. At present there are three. With each additional puck light the load changes. The CC keeps all of the pucks lit at a set level. Adding an additional puck will not change the brightness because the CC will vary the voltage in order to maintain a total current of whatever it is set at.

If it were a CV supply then with each additional puck the brightness will begin to fall. At first the drop in lumens will be practically un-noticeable. However, as the number of pucks grow the brightness will diminish.

Just for clarification, my puck lights are designed to plug in one to the other in series. Each connector has a built-in switch. Positive goes to the first puck the to the second then to the third, then to the switch that connects the positive line back to the negative line, then back through each puck back to the supply. I'm not certain of the exact wiring on each puck because they're mounted on a heatsink, and there are no traces visible on the LED side.

So don't let CC and CV confuse you. They are exactly what their name says.