Upgraded Madcatz SE stick - Hard Kick and 3K randomly stop working

First off, I searched for similar topics but didn’t really find anything relevant to my problem.

Madcatz SE Fightstick (upgraded with Sanwa stick and buttons)

The stick belongs to my friend, and the HK and 3K buttons randomly stop working (always at the same time). This happened before and after he upgraded to Sanwa parts. Reconnecting the stick fixes the problem but it happens again later. Sometimes frequently, sometimes just once.

We tested the breakaway cable and that didn’t solve anything. My only guess is the way the USB cord is soldered to the board, or something with the quick disconnects.

Anyone have any knowledge about this particular problem? I have the same stick (also upgraded) but I don’t have this problem.

Bad PCB, not uncommon. In fact it is usually LT & RT that fail together

There’s a thread but no guaranteed solutions.

http://shoryuken.com/showthread.php?t=178112