k95 rgb platinum Tracing NXP chip on pcb - help needed please

[CobraStrike]

Hi all,

New poster and recent convert to mechanical keyboards, but hoping for a little help from the electronically minded please :)

 

My son managed to spill a drink on my K95 plat and as a result a particular group of keys have stopped working. I have a plan about how to repair this (or at least try) but i need some kind assistance from someone who:

*Has a K95 Platinum

*Has already voided their warranty by opening the back case (and preferably has a K95 plat that is still open to avoid the hassle of a teardown)

*Owns a multimeter to do a quick circuit trace for me.

 

With the keyboard base off and looking at the pcb (green circuit board) from underneath, at the bottom of the keyboard behind the "down arrow key" mechanical switch there should be a small brown diode labelled DA95. The right hand end of this has a black stripe around it.

 

All I need some kind soul to do is put a multimeter in continuity mode (beeps at you when you connect to two ends of a circuit, piece of wire, etc), and put one probe on the small right hand end contact of that diode DA95 where it has the black stripe.

 

The other multimeter probe then runs around the 100 pins on the main NXP chip (located slightly above and to the left of this switch) until you hear it beep, basically confirming which pin on the main NXP LPC11U68JBD100 chip is linked to the negative end of that diode.

 

This will help me enormously, in that my motherboard circuit from that diode back to the NXPchip has been broken by the spill, and if I can bypass it and hardwire it back to the correct pin, seven keys on my beloved K95 will instantly start working again! :laughing:

 

Happy to supply a supporting picture if needed.

 

Thanks in advance to anyone who can help me out :D:

[CobraStrike]

Hi all,

 

After about 60 hours work I have managed to trace all the switch pinouts from the main NXP chip myself and solve my broken circuit in the process. If anyone else finds themselves in this situation, let me know as I may be able to assist YOU :)

[mccartt]

Similar issue (I think). My left arrow key stopped working and after cracking it open I see a rusted out diode. How do I identify (and where can I get) a replacement diode?

Edited January 10, 2020 by mccartt

[mibenavi]

I am really embarrassed to zombie this thread from two years ago, but oh mighty @CobraStrike, if you are still online and with the circuit trace on hand, can you be the divine angel that saves my K95 and share me the file?

[kemo]

Interesting to see a diode listed as "DA". Mibenavi, is there anything that you can make out from the marking on your diode?

 

It'll be pretty difficult to figure out the voltage and current rating of the diode without more info. The package/case could be determined by measurements, but you'll need to have something precise (is it MELF, Mini-MELF...).

 

If you get some info, I'm very rarely on here. PM me if possible and it should send me an email notification.

[CobraStrike]

@Mibenavi, I've messaged you with what I have, good luck with your recovery.

[CobraStrike]

(DA94 goes to Left Arrow key and NXP pin 87). This is shared with DA100, DA111, DA82, DA70, and a few others, so you may find one of them is not in "much use" and steal it to repair your arrow key. I'd go for something like DA70, with the Document Icon on the key, I've never used that ha ha. Anyway, take a look at the info I've sent and pick one to salvage, that's kind of how I worked it.

[Insidethescull]

Could you please share the file with me as well? I’d love to save my board!

[388849]

Hello, Could You Please tell me where Goes 7UJN <<< keys on that chip? Seems like i have similar problem and it would be appreciated if you can help me 

[sirromeoj]

Hello CobraStrike

If you read this message at some point could you also send me what info you have one trace layouts as my INS and Page Up keys have broken.