Author Topic: CREE Q5 Repair Advice  (Read 486 times)

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Offline UltimateX

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CREE Q5 Repair Advice
« on: September 10, 2019, 02:40:17 pm »

Just recently my CREE Q5 torch stopped working and I traced the fault to a dry joint on one side of the LED driver board diode.  However, as I was removing the driver board an SMD capacitor (I think), suffering from the same dry joint issue, popped off the PCB never to be seen again.

I have re-soldered the diode to the driver board and replaced the original brittle solder on several points on the driver board and the Q5 LED now lights but I am missing this capacitor, which I would like to replace (see attached photos).  I tested the remaining other cap with my component tester and it detects its value as 10uF, but I am not sure if this has any relation to the missing one.   Would anyone have the same single-mode Q5 CREE torch they have worked on and know the value of this cap (or resistor?) or, in any event, be able to advise me on what capacitor I need to use to replace this cap please? 

Many thanks in advance.

« Last Edit: September 10, 2019, 02:55:16 pm by UltimateX »

Offline shakalnokturn

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Re: CREE Q5 Repair Advice
« Reply #1 on: September 10, 2019, 10:20:08 pm »
According to strong exuberant joyful lucky Shanghai Yuxin Electronic Technology Co., Ltd, that would be something like a 10uF MLCC.

If components are dropping off the IMS either it was very badly manufactured to start with or it's running way too hot (crap design either way...), a little thermal compound around the edge and a decent tightening of the fastening ring may help in the second case.
« Last Edit: September 10, 2019, 10:23:18 pm by shakalnokturn »
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Offline UltimateX

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Re: CREE Q5 Repair Advice
« Reply #2 on: September 10, 2019, 11:34:45 pm »
Ah!  Thank you so much for finding the schematic shakalnokturn - that's exactly what I couldn't find.  :-+ :-+ :-+  I suspected as much regarding the cap value and soldered in a 10uF cap earlier, which seemed to have no adverse effects.  Fortunately, I don't have to back out that change now you've confirmed it's correct with the schematic.  Very much appreciated - thanks again. :)

And just to add, I think the lead-free solder the manufacturer used was poor or perhaps here was too little flux.  In any event, I decided to re-seat and solder all the components to avoid having to reopen the torch again (hopefully).  Everything seems be tight and working well now.  I know I dropped it a couple of times but still it's supposed to be a pretty rugged torch judging by its housing.   
« Last Edit: September 10, 2019, 11:38:36 pm by UltimateX »

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