I would be eternally grateful if someone could help me debug my issue.
The following keys are not testing correctly: K35 (~), K34 (tab), K33 (A), K37 (1), K64 (Y), K74 (J), K75 (I), K76 ( 8 ), K77 (9). It appears that I have a problem with columns 7, 3, and possibly 6.
Here are my attempts to fix the issue:
1. Replaced the diodes using through hole (1N4148) - made sure the polarity is correct
2. Replaced the didoes again using fresh 1N4148
3. Replaced the diodes using 1N4148W surface mount diodes
4. Re-flowed solder on the controller using fresh solder paste + lots of flux
None of the above seemed to fix the issue. This is before soldering any switches. I am simply soldering the diodes and testing the board operation PRIOR to soldering any switches. All diodes test ~.650V forward voltage drop across the diode. Key presses are simulated using EK Switch Hitter utility and Notepad + shorting the switch pins. The failing keys register no input at all, no key press is registered.
Tools used is a Yihua 898BD+ temp controlled soldering station with SAC305 solder.
Pictures at attached (excuse the quality, all I have is a cellphone and point and shoot).
http://imgur.com/a/Mq7LW