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geekhack Community => Keyboards => Topic started by: Bakgrund on Mon, 29 December 2014, 11:03:48

Title: QFR lalt not working
Post by: Bakgrund on Mon, 29 December 2014, 11:03:48
Hello, I got a Cm storm quickfire rapid with red cherry mx switches, and the left alt gr button won't work, I've tried another computer and it didn't respond there either, what might be wrong? fauly switch? I couldn't see anything wrong with the pcb when I took it apart. Is it possible to solve this problem?

I was also thinking of trying to short the two soldering points myself, to see if it's the switch, but I'm unsure about what points I should short. I've attached an image of the pcb so if someone could tell me what points I should short that'd be great.

Thanks!
Title: Re: QFR lalt not working
Post by: Grendel on Mon, 29 December 2014, 12:17:45
The two solder joints left of where it says Alt_L, below the black part sticking through the PCB (that's the center of the Alt_L switch.)
Title: Re: QFR lalt not working
Post by: tp4tissue on Mon, 29 December 2014, 12:19:19
I think there's been an elevated number of posts on keys not working in the WINTER thus far..

probably due to the cold causing the Metal plates to contract, and thus the pcb is being cracked..

the 2 on top of the black nub..

the switch is almost 100% likely to be fine..  it's the pcb.. minor crack fracture somewhere.

Just follow the traces and bridge it.
Title: Re: QFR lalt not working
Post by: Bakgrund on Mon, 29 December 2014, 12:29:27
Okey I tried to short the two correct contacts and it didn't work so I suppose the pcb is cracked then? Or can it be the diode? I don't know where to start, what more troubleshooting should I do, if necessary?
Title: Re: QFR lalt not working
Post by: Puddsy on Mon, 29 December 2014, 12:58:59
Did you try reflowing the solder?
Title: Re: QFR lalt not working
Post by: Bakgrund on Mon, 29 December 2014, 13:20:35
Did you try reflowing the solder?

Hmm, I think I might be on the right track now, I looked at it more carefully now and I think i see a crack (attachment "1.png"). I then tried to melt the solder right now as you told me, and a whole "flake" (attachment "2.png") seem'd to come off, I supposed that's a piece of the trace? Attached some detailed zoomed in pics. Is this something that's possible to fix? It's pretty weird anyway, as I've never raged at the keyboard or anything.
Title: Re: QFR lalt not working
Post by: Puddsy on Mon, 29 December 2014, 14:05:49
ah, the pad is lifted

that's not a difficult fix actually

i just forget what the fix is :|
Title: Re: QFR lalt not working
Post by: rowdy on Mon, 29 December 2014, 22:54:44
What surprises me the most is that tp4 has contributed something technically accurate and useful :eek: :p
Title: Re: QFR lalt not working
Post by: nubbinator on Mon, 29 December 2014, 22:57:36
ah, the pad is lifted

that's not a difficult fix actually

i just forget what the fix is :|

The easy fix is to bridge the trace with with some wire.
Title: Re: QFR lalt not working
Post by: Bakgrund on Tue, 30 December 2014, 09:42:32
Thanks for everyone's help, just scraped some of the green coating thing off and put some solder on there, and now it works fine. Could be prettier, but who cares, it works!
Title: Re: QFR lalt not working
Post by: Puddsy on Tue, 30 December 2014, 15:59:50
Thanks for everyone's help, just scraped some of the green coating thing off and put some solder on there, and now it works fine. Could be prettier, but who cares, it works!

hey, if it works it works

thanks for taking pics too, will be useful for anyone who has this issue in the future