Fried 3 drivers and 2 buttons on a fw1a xhp50.2 3v install

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trailhunter
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Fried 3 drivers and 2 buttons on a fw1a xhp50.2 3v install

I literally fried 3 drivers, each time taking one out and wondering why. I didnt see any noticeable shorts. At this time I’ve attributed the shorts to the LED. Powering the led with a PSU works fine. Is it possible that the xhp50.2 caused this?

Sirstinky
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The xhp50.2 in 3v will draw massive currents with a fet driver on turbo and a low resistance cell. I’m taking 8+A. I get 5.6A through my multimeter (not clamp) on a so-so fet driver in a different light so it’s more like 7 or 8A in reality. If your switch can’t take it, or your driver can’t handle it then things will melt or blow. What driver are you using?

trailhunter
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Sirstinky wrote:
The xhp50.2 in 3v will draw massive currents with a fet driver on turbo and a low resistance cell. I’m taking 8+A. I get 5.6A through my multimeter (not clamp) on a so-so fet driver in a different light so it’s more like 7 or 8A in reality. If your switch can’t take it, or your driver can’t handle it then things will melt or blow. What driver are you using?

It’s the stock driver from an fw3a, I’d imagine it can support the xhp50.2 no?

Cereal_killer
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Where are you getting spare fwxa drivers?

 RIP  SPC Joey Riley, KIA 11/24/14. Now I am become death, the destroyer of worlds.

trailhunter
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Cereal_killer wrote:
Where are you getting spare fwxa drivers?

From my other fw3’s which are now driverless! why do you ask?

Cereal_killer
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Just curious. What’s your plan with them? Gonna try to repair the now bad ones?

 RIP  SPC Joey Riley, KIA 11/24/14. Now I am become death, the destroyer of worlds.

trailhunter
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Cereal_killer wrote:
Just curious. What’s your plan with them? Gonna try to repair the now bad ones?

yeah or hopefully order some from lumintop or neal or neal. Toasted drivers on my fw3s that I use often. I was just so driven to make it work and now I paid the price:)

Cereal_killer
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Unless you smoked traces on the boards you can always rebuild them.

 RIP  SPC Joey Riley, KIA 11/24/14. Now I am become death, the destroyer of worlds.

trailhunter
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Ah is it worth the hastle?

Cereal_killer
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A few cents worth of chips and a quick reflow vs buying all new drivers from lumintop and waiting on the slow boat? Of course it’s worth it!

Plus it’s not like every component on the drivers are bad. You’ll need to diag them to know what actually needs replacing though.
FET is probably good, resistors and caps will still be fine. If you can tell us the failure mode I can pinpoint it more specific for you but at most I can’t imagine needing more than the MCU and some/all of the 7135’s

 RIP  SPC Joey Riley, KIA 11/24/14. Now I am become death, the destroyer of worlds.

trailhunter
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Oh okay, I’ll pick them out of the trash can then. The springs got vaporized but that’s and easy fix

The emitter alone shouldn’t have caused this chaos though right?

Cereal_killer
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Springs melting is a dead short from batt+ to batt- or LED-. Could of been ssering, could of been shorted by the reflector.

They might be ok with just new springs, the MCU should of been protected by the reverse polarity diode. Might need new 7135s…

 RIP  SPC Joey Riley, KIA 11/24/14. Now I am become death, the destroyer of worlds.

CRX
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How did you have the reflector sitting? Insulated?
The XHP50.2 3v can be shorted if you have the reflector sitting on the corners.

contactcr
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Yes what they said. Whenever I build a reflector light I do a quick function test without the reflector. If in doubt (some people just do it 100% of the time) cover the bottom of the reflector with kapton tape and/or make your solder blobs smaller and more towards the outside edge. The reflector opening is barely larger than 5mm so you might even need to ream that out if your centering ring wont cover you from what CRX describes.

trailhunter
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Hi all, so heres the aftermath, hopefully these photos can give a peak as to what the problem might be (excuse my shitty solder work, this was after multiple solder/desolder attempts.

https://imgur.com/a/t7iMrwv

Sirstinky
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Looking at those pictures, did you cut down the mcpcb at all to get it to fit inside the fw1a head? It’s possible some of the traces were exposed and causing a short. Otherwise I can’t see where anything is shorted. Maybe try bypassing the spring?

KawiBoy1428
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Check for continuity between LED + and the back of the mcpcb, possible solder bridge between anode and DTpad??????

KB1428 “Live Life WOT

trailhunter
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Yeah I did have to cut it down a bit. I’ll try another mcpcb to see if that was the issue.