MJ850 - cheap. Too good to be true?

[Chilly_Dipper]

It looks like that it's the rectifying diode on the output of the buck converter has melted. This is a sure sign that the component was stressed beyond it's power rating. Typically these driver boards are rated for ~1A draw, but by changing the feedback resistor (typical hack for these) you can get the output current up to 1.5 to 2A.

If you look at the data sheet for the XPG line of LEDs you'll see that they are rated for a nominal current of 1.5A to get the most light out of them. Bad fore sight in design is what this is.

Dear Forum members and readers,

I had a tool made to extract the brass ring. Indeed, Michael was right, it was the suspect component on the PCB that failed. It was fried beyond recognition. There is even a small vulcano on top.View attachment 105888

Sape

 

[ano123]

I think usd350 for 1200lumens light are a little expensive.lol

Hi,

In my search for a good divelamp for around $350 I found a much cheaper lamp using similar leds the expensive ones do...

the mj850 at 1200lm

The cheaper models look complete and seem to be built to standards, but would I trust these on my liveaboard...?

TIA

Maurice

 

[maegez]

Hallo Michael

Verkaufst du diese Module immernoch? Bin schon lange auf der Suche nach einem Ersatzmodul und bin leider erst jetzt auf das Forum gestossen...

Gruss

Markus

The price for a 810 replacement PCB is 9€ (13$), a 850 replacement PCB costs 12€ (17$)

Michael

 

[victorzamora]

Hallo Michael

Verkaufst du diese Module immernoch? Bin schon lange auf der Suche nach einem Ersatzmodul und bin leider erst jetzt auf das Forum gestossen...

Gruss

Markus

That was said over three years ago.