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Offline pixelpusher

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PCB HELP!
« on: Mon, 06 February 2017, 21:30:36 »
Okay, so this is a GH60 Satan (RevCHN).  I tested it before the build with switchhitter and paperclip all is well.  Built, customized firmware, used for a week... fine.  Added in some sip sockets and leds on bottom row and now 9, o, l, and , don't work.  It's a full column.  There  is nothing on those keys near where I added the sip sockets.  No random solder shorting anything.  The non-working switches are on D46,D47,D48, and D49 (likewise R44, R45, R46, and R47).  I'm assuming those are diodes and resistors?  I really don't know enough to fix the issue.  I went ahead and put sips and an led in the top switch to see and it does have power to the led.

159857-0
« Last Edit: Mon, 06 February 2017, 21:38:58 by reececonrad »
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Offline pixelpusher

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Re: PCB HELP!
« Reply #1 on: Mon, 06 February 2017, 21:41:19 »
This is such an awesome board, I just don't know how to fix it :(
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Offline pixelpusher

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Re: PCB HELP!
« Reply #2 on: Mon, 06 February 2017, 23:07:37 »
Just noticed the space bar is also no longer working. This key DOES have a working led in it
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Offline stoic-lemon

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Re: PCB HELP!
« Reply #3 on: Tue, 07 February 2017, 03:45:01 »
Did you do the paperclip test again?
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Offline pomk

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Re: PCB HELP!
« Reply #4 on: Tue, 07 February 2017, 03:59:36 »
If an entire column is affected, like in your case, it is likely that the problem lies closer to the MCU. Can you get a close up photo of the MCU area?
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Offline pixelpusher

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Re: PCB HELP!
« Reply #5 on: Tue, 07 February 2017, 07:28:14 »
Quote from: pomk on Tue, 07 February 2017, 03:59:36
If an entire column is affected, like in your case, it is likely that the problem lies closer to the MCU. Can you get a close up photo of the MCU area?


I didn't see anything suspicious looking there but it's hard for me to see that close up and I don't know which pin would effect that column.  I have a message in to the tech from the eBay seller as well
« Last Edit: Tue, 07 February 2017, 07:40:29 by reececonrad »
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Offline a-c

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Re: PCB HELP!
« Reply #6 on: Tue, 07 February 2017, 11:58:50 »
Follow the trace all the way back to the MCU. Look for breaks or shorts.
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Offline pomk

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Re: PCB HELP!
« Reply #7 on: Tue, 07 February 2017, 12:07:32 »
The mcu area looks good, strange. As pointed out already, follow the trace to see if anything suspicious is on the way. If you can't find anything you can try to reflow all the joints connected to the trace.
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Offline pixelpusher

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Re: PCB HELP!
« Reply #8 on: Tue, 07 February 2017, 13:33:22 »
I don't see anything wrong.  I've followed all of the traces and I don't see any damage.  I've ordered a new PCB.  I don't mind the expense, but what is going to suck is desoldering everything.  That's the part I'm pissed about.  Also, the unsolved mystery of what went wrong.  This board had been up and running for a week with no issue.  I just don't know what I did to it and that's frustrating.
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Offline pomk

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Re: PCB HELP!
« Reply #9 on: Tue, 07 February 2017, 13:51:52 »
Try re-flowing all the pads that are connected to the trace, mcu pin included. Other than that is difficult to do without a multimeter.
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Offline tp4tissue

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Re: PCB HELP!
« Reply #10 on: Tue, 07 February 2017, 14:18:41 »
get ur light in there on the mcu pins make sure there are no shorts underneath.. sometimes the solder gets in there..

when you follow the trace, you're not going to be able to see cracks..

what you want to do is Bridge certain keys to the mcu and see if it works.  you can just solder to a point closest to the mcu, don't solder directly to mcu ..
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Offline pixelpusher

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Re: PCB HELP!
« Reply #11 on: Tue, 07 February 2017, 14:49:35 »
Quote from: tp4tissue on Tue, 07 February 2017, 14:18:41
get ur light in there on the mcu pins make sure there are no shorts underneath.. sometimes the solder gets in there..

when you follow the trace, you're not going to be able to see cracks..

what you want to do is Bridge certain keys to the mcu and see if it works.  you can just solder to a point closest to the mcu, don't solder directly to mcu ..

okay, so I can probably so some safe testing by just holding a jumper to a MCU pin and one of my switches.  So what I need to know is which pin on the MCU and what to jump it to on the switch, right?  The + switch terminal?  The Diode on the switch?  I can put tape on over the switch to keep the key depressed.
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Offline pomk

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Re: PCB HELP!
« Reply #12 on: Tue, 07 February 2017, 15:26:23 »
Just follow the trace, it ends up at the pin you are interested in. That pin should be connected with a temporary jumper to the switch pin opposite of the diode and you won't even need to depress a button to confirm that there is a connection problem somewhere along the way.
« Last Edit: Tue, 07 February 2017, 15:28:29 by pomk »
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Offline pixelpusher

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Re: PCB HELP!
« Reply #13 on: Tue, 07 February 2017, 15:39:27 »
I'm confused as to where this trace goes.  Here is 46

159925-0


And here is 49

159923-1

Where does it go back to the mcu?  It looks like they both stop
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Offline pomk

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Re: PCB HELP!
« Reply #14 on: Tue, 07 February 2017, 16:08:09 »
It continues on the other side at the point with the via (small hole/dot)
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Offline pomk

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Re: PCB HELP!
« Reply #15 on: Tue, 07 February 2017, 16:14:11 »
I forgot that you have assembled it and probably used a plate... tough luck trying to follow it to the mcu without a multimeter or the shematic.
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Offline pixelpusher

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Re: PCB HELP!
« Reply #16 on: Tue, 07 February 2017, 16:44:54 »
Okay that makes sense.  I'll have to desolder tonight. I had planned on it anyway.  I appreciate all of the help
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Offline pixelpusher

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Re: PCB HELP!
« Reply #17 on: Wed, 08 February 2017, 17:16:39 »
Great news!  I fixed it! I wish I had taken pictures, but once I got it all desoldered and looked on the back side, I followed that trace and found the smallest nick in it, right above the space bar area.  I was too excited when I found it to take pictures; I just wanted to hurry and see if that was the fix, and it was! I vaguely remember trying to get it out of the case and having my screw driver slip up into that area.  That must have been what did it!

Anyway, I scraped back the trace on either side and soldered a teeny tiny copper wire and it frigging works!  I was confused about the space bar not working, but I remembered that was a crappy version of the firmware that I had loaded on it in a hurry and forgot to add the spacebar.  Thanks a lot for your help, guys.  Lesson learned.

 :thumb: :thumb: :thumb: :thumb: :thumb:
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Offline stoic-lemon

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Re: PCB HELP!
« Reply #18 on: Wed, 08 February 2017, 19:21:17 »
lol You didn't mention the screwdriver slip. Glad you got it fixed up.
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Offline Moistgun

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Re: PCB HELP!
« Reply #19 on: Wed, 08 February 2017, 19:40:09 »
Quote from: reececonrad on Wed, 08 February 2017, 17:16:39
Great news!  I fixed it! I wish I had taken pictures, but once I got it all desoldered and looked on the back side, I followed that trace and found the smallest nick in it, right above the space bar area.  I was too excited when I found it to take pictures; I just wanted to hurry and see if that was the fix, and it was! I vaguely remember trying to get it out of the case and having my screw driver slip up into that area.  That must have been what did it!

Anyway, I scraped back the trace on either side and soldered a teeny tiny copper wire and it frigging works!  I was confused about the space bar not working, but I remembered that was a crappy version of the firmware that I had loaded on it in a hurry and forgot to add the spacebar.  Thanks a lot for your help, guys.  Lesson learned.

 :thumb: :thumb: :thumb: :thumb: :thumb:

man, that is a lot of work, but im glad you got it back up and running!
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Offline pixelpusher

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Re: PCB HELP!
« Reply #20 on: Wed, 08 February 2017, 20:29:54 »
Quote from: stoic-lemon on Wed, 08 February 2017, 19:21:17
lol You didn't mention the screwdriver slip. Glad you got it fixed up.


I honestly had forgotten about it. All I could think about was soldering in the LEDs and I didn't know what I would have done wrong to it
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Offline pomk

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Re: PCB HELP!
« Reply #21 on: Thu, 09 February 2017, 01:22:26 »
Glad to hear!
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