Broken component in UFO LED light - Can I fix it ?

[BirthdaySoup]

I've got a 90W UFO LED light in which the internal cooling fan has given out. The LED array still functions fine, but overheats the unit. The company who makes this light has discontinued the range, so I have a semi-functioning light which I'd rather fix than consider dead. I'm at a very amateur level of electronics knowledge - I can wire stuff to other stuff if directed and have a rough grasp of what's happening in circuits but would rather someone was able to pinpoint what's wrong before I screw it up. It seems to be a fairly generic light and build style and I figured someone out there has fixed one up before.. Here goes

I've opened up the unit, I know that the larger black boxes on either side are the LED power supplies, but don't know exactly what the box leading to the fan is. I removed it and enclose a picture of the breadboard inside the casing. Is this a part I can buy off the shelf or something I would have to literally put together myself ?





If anyone can advise me in any way, I would much appreciate it

Thanks !

 

[lushgreen]

Looks like a 12 volt 120mm computer fan. They're easy to source and cheap. You want one with ball bearings as they last longer.
The smaller of the black boxes is most likely a small 12v power supply that takes your 110v AC input and changes it to 12v DC output just to run the fan. Probably used by the manufacturer in larger units that take 2 or 3 fans hence the 3 outputs.
Ideally you'd find a fan with the same connector but that's probably unlikely as it doesn't look like a standard plug to me.
Cut the red and black wire going from the dead fan, remove the dead fan, replace with a new one, twitch the red wire from the new fan to the red wire from the old. same for the black wire. Tape the bare wires up so they don't short out.

 

[BirthdaySoup]

Thanks for the reply !

I figured I should get a new fan anyway, but is it possible for the step-down transformer to go as well ? I have no way of testing currents or anything, but it would be cheaper to buy both components at once if necessary..

Thanks again !

 

[lushgreen]

Be harder to find another power supply and for you to wire it in as you're dealing with mains power. Easier to try a new fan first.

 

[Dave Groomer]

You should be able to get a fan almost anywhere...Staples, Radio Shack. You can probably find one for about $10. If that doesn't fix it, you are only out the $10.

Good luck.

 

[BirthdaySoup]

I installed a new fan which is the same specs except for being three pin instead of two. I isolated the tachometer wire and wired the red and black to the step down transformer, but the fan still won't work. I tried connecting the fan to another of the red and white outputs on the power supply, and still nothing. I'm assuming the power supply unit is gone - is this something I can try and replace myself ?

 

[lushgreen]

Easiest way would be to connect an external 12v DC plug pack to the fan and plug that into the same timer circuit as the lights.
Finding something that fits inside the light again, more difficult.

 

[BirthdaySoup]

Easiest way would be to connect an external 12v DC plug pack to the fan and plug that into the same timer circuit as the lights.
Finding something that fits inside the light again, more difficult.

I have a spare 12V DC and can easily install it outside the unit. I assume this means totally removing the step-down transformer, right ? Is there any effect on the LED array and power loads they'll receive if I do ?

 

[lushgreen]

As far as I can tell, if you just leave the white plug going to the fan power supply unplugged, the rest of the light should work perfectly fine. The external plug pack will power the fan and stop the overheating issue. Won't be pretty but it will be working 100% normally and won't require mad electronic skills.
Probably want a plug pack that is rated at 500ma or more.

 

[BirthdaySoup]

Cool, I have a 600ma that'll do it. Thanks very much for all your help Lushgreen. Will let you know !

 

[lushgreen]

any luck?