How to Troubleshoot & Replace Whirlpool AP6019803 / WPW10336131 Electronic Control Board

According to the manual, error code F73 indicates an issue with the control board(s). There are two in the MGDB850WQ0. One is for the control panel and the other is a power control board for the motors / sensors. From what I read from others on this site, the control panel board is the likely culprit. Ordered a replacement board WPW10336131 and swapped them out. Dryer now works fine. One note is the circuit board itself comes sandwiched between a black plastic front cover (shown in the picture) and a white plastic cover. I could not figure out how to get the black plastic piece off, and so I only swapped out the circuit board and the white plastic back cover. It was a simple replacement as it only involved 4-5 screws. 

After utility power returned the display shows 3 dashes after rotating the knob. Trying the tech sheet diagnostics generated a different code every time I ran it. More than a dozen different error codes, many of them not even defined. Another sign is some functions of the User Interface Control Board not working; like LED's out and simple functions like the drum light not working. The fix: replace USER INTERFACE CONTROL BOARD. 

Replaced control panel 

Just replaced Card, only card 

Found part in online drawing, ordered part. Part arrived as promised and was a direct replacement. Took less than 15 minutes to change out.