[Help] One key/switch not working [SOLVED]

[searscatalog]

So I have a Keycool 84 Hero 2 with Cherry MX Reds I purchased from Massdrop over a year ago. Upon delivery my Down arrow did not function.

At first just pressing down and wiggling the key/switch seemed to bring it back, maybe a month working it stopped again and doing the wiggle trick help for a short time until it stopped completely. At that time I opened the case and checked the solder joint. They looked cold so I decided to re solder by sucking up the old and putting new solder on. This worked for several months until about 3 weeks ago when it just stopped working again.
Ordered a few spare switches and decided to replace the entire switch today. Unsoldered the led/switch and replaced with a new one and still no input from my down arrow. Led still works after uninstall/reinstall.
Could a diode be out , trace damage, or just my PCB gone bad? Hoping some experienced eyes can help me out.

Included here are pictures of the area. http://imgur.com/a/swQ3s

I did notice solder on the diode at D513 when I very first opened the case, as well as some oxidization on joints around where DOWN is. Thank you for any input.




[SOLVED] Was the diode at D513 not working. Replaced with new and now have a completely functional keyboard again.

[tp4tissue]

do you have a multimeter ?

[tp4tissue]

This looks like a trace crack..  could just be photo noise though..

[searscatalog]

This looks like a trace crack..  could just be photo noise though..

(Attachment Link)

I do have a multi meter, how should i check it?

I'll see if i can get a better shot of that trace

[tp4tissue]

This looks like a trace crack..  could just be photo noise though..

(Attachment Link)

I do have a multi meter, how should i check it?

I'll see if i can get a better shot of that trace

put it on the beep setting,  or the resistance setting,  then go from the switch joint  to wherever the next closest open copper/joint is.

[searscatalog]

This looks like a trace crack..  could just be photo noise though..

(Attachment Link)

I do have a multi meter, how should i check it?

I'll see if i can get a better shot of that trace

put it on the beep setting,  or the resistance setting,  then go from the switch joint  to wherever the next closest open copper/joint is.

Sorry for the delay, life/wife/dinner

Well my multimeter is old and annoying but I can get a reading with key presses, same reading for other switches. So it seems the switch works but signal must be lost somewhere between there and my pc


Here are two more shots of the area
http://i.imgur.com/0oMpiqq.jpg
http://i.imgur.com/HLUJu4y.jpg

[searscatalog]

Ok, I got my multi meter to stop being a little s*** and checked for continuity between the switch and diode. Looks like it's not passing thru the diode on that switch. Checked the same way on other switches all over the board and get around the same reading. Just not that one, looks like I just need a diode.

[tp4tissue]

it must've been just dust then..

Check these paths..



is this board have a plate in the front or pcb mount.

[searscatalog]

Tough to get a detailed shot of the traces and such with my camera. Not seeing any trace damage in the area by eye.

It's a plate mounted board.

From my testing it looks like nothing is passing thru the diode on D513

Diode 1N4148   would be the replacement I would need, correct?

[tp4tissue]

Tough to get a detailed shot of the traces and such with my camera. Not seeing any trace damage in the area by eye.

It's a plate mounted board.

From my testing it looks like nothing is passing thru the diode on D513

Diode 1N4148   would be the replacement I would need, correct?

diode only goes through in one direction, try the other direction.

[searscatalog]

diode only goes through in one direction, try the other direction.

[SOLVED] It was the diode at D513 not working. It split in two while unsoldering from the board. Replaced with new and now have a completely functional keyboard again. Thank you for your help tp4tissue!