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geekhack Community => Keyboards => Topic started by: Volucris on Sun, 06 January 2019, 16:02:46

Title: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: Volucris on Sun, 06 January 2019, 16:02:46
Tragically I spilled a beer on my Leopold FC900R and two keys stopped working even after a flush of the board. The left control, and left windows key died. A continuity test showed little to no continuity in use, so I desoldered the switches, disassembled, and cleaned them. After soldering both switches back in place, the left control key works fine. However the left Windows key, while passing continuity for the switch itself, will not work in the OS. I can't see any obvious damage to the board but have not removed the full plate (have to desolder all switches to remove the plate). I've also tried dip switch combinations per the Leopold brochure in Korean.

I've checked the nearby SMDs, and the D86 and D17 diode both seem toast. The other diodes of similar placement are reading about 720 on my multimeter. I suppose the next question is what specific diodes do I replace these with? Or could they be fine and I'm not checking them right? The rest of the keyboard works fine in keyboard tester. And I suppose I'm not fully understanding why both of those SMDs would be bad, but the left control still works.

Some pictures:
(https://i.imgur.com/PeN6sIG.jpg)
(https://i.imgur.com/7Mx2iZK.jpg)
(https://i.imgur.com/m2fHJaF.jpg)
(https://i.imgur.com/NEYvt9I.jpg)

Thanks for any help provided.
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: tp4tissue on Sun, 06 January 2019, 16:59:19
if you're sure it's the diode, just put in new ones, they don't have to be smd, you can get any diodes it'll prolly work.
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: Sup on Sun, 06 January 2019, 18:01:07
Your keyboard uses SMD diodes these should work fine.

https://www.digikey.com/product-detail/en/diodes-incorporated/1N4148W-7-F/1N4148W-FDICT-ND/815280#images-1
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: ander on Sun, 06 January 2019, 22:12:55
Hope you manage to fix it—but if you don't, keep in mind that Shift+Esc opens the Start Menu too.
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: Volucris on Fri, 08 February 2019, 21:51:41
Update:

Ordered some SMDs on eBay and was able to replace them on this board. Works just fine now. Not the same resistance as the stock SMDs, but close enough.
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: suicidal_orange on Sat, 09 February 2019, 06:38:51
Glad you got it working :thumb:

Quote from: ander on Sun, 06 January 2019, 22:12:55
keep in mind that Shift+Esc opens the Start Menu too.
It's Ctrl+Esc for me - is this an ISO quirk?
Title: Re: Liquid Spill Killed my Left Windows Key - FC900R - SMD replacement?
Post by: fer.real on Sat, 09 February 2019, 06:47:03
Quote from: suicidal_orange on Sat, 09 February 2019, 06:38:51
Glad you got it working :thumb:

Quote from: ander on Sun, 06 January 2019, 22:12:55
keep in mind that Shift+Esc opens the Start Menu too.
It's Ctrl+Esc for me - is this an ISO quirk?

No, it's Ctrl + Esc for everyone.
https://support.microsoft.com/en-us/help/12445/windows-keyboard-shortcuts