LED Main Lamp Issue

At some point my Cyclops LED driving lamp stopped working. As it's LED, I assumed it was probably a wiring issue and not a failure of the LED. I think it actually did just die, possibly overheated or fried a circuit board. Just wanted to share what I found so I don't waste money on a replacement when it was something in the outer loop.

Casual observation: Cooling fan works as it should; Some flux type material around the threads of the brass (?) end cap at the LED end of the lamp; No scorching or evidence of blown circuit board; All visible wires connecting the LED boards undamaged; Resistor/transformer looked pristine and no broken or kinked wires; H4 terminal looks fine; I have a custom light kit tapped off the 3 leads running to H4 connector and they work perfectly; OEM LED running lights work as designed.

Deeper look: I tested voltage from the main wiring loom and the LED connections. I'm not great with a multimeter but think I got a good read. So, there are 4 polls from the main loom to the headlight housing. I've ran a lot of taps on this over the years so assumed I had trouble here. With AC power on, I got 12 V from the poll just under ground, 12 V from the 3rd, and about 5.5 V from the bottom poll. When I hit the high beam switch, polls 3 and 4 swapped the 12 V and 5.5 V values. I think all this makes sense. I got similar readings on the transformer in line for the LED. I cleaned up the abused main loom wires anyway and it didn't change anything.

I tore the bulb down as far as I could. Like I said, top of boards look good but I couldn't get deeper as the two screws retaining the last shield must have been torqed by the Hulk...can't break them. That weird flux around the brass cap was the only oddity. It resembled solder and had an oily flux around it.

I'm sure they have a decent warranty but mine is probably 5 years old. There's 4 bulbs, 2 on each side. And they all failed at once.

I'm gonna look for an H4 halogen and order a new Cyclops. I threw my OEM away last year after toting it around for years.

Yes, Cyclops H4 3800L from the 2015-ish era, to be specific. I think the way the 5.5V cycled between the two polls with the bright switch made sense as it was switching from low-beam to high-beam. The LED has a rectifier/transformer that should have handled voltage regulation. Like I said, worked 4.0 until it just stopped, and up until about 3 months ago I rarely drove at night. I noticed a couple months ago when the high-beam dash indicator started flashing when activated. My aux lamps still work but it was getting a fault from the OEM fixture. I found an H4 halogen at the store and will drop it in soon for a verdict.

Oh ya, so if your dash high-beam indicator flashes when you hit the switch, you've got a main lamp issue.

Mine never did that prior to lamp failure.

What's the slim mount LED brand?