Really appreciate your help with this but I did eventually get it working with one configuration. Hopefully it doesn't give me any more trouble...

It sounds like the ribbon cable connecting the 2 PCBs is getting pinched/fucked when you close the case. Make sure you insert it PERFECTLY and that it doesn't fold or bend funny when you close it up. Unfortunately DMGs are old and the ribbon cables become very fragile over time. If nothing works, try to find a replacement cable or front PCB.

So I just put in a new backlight with a new power LED, which went fine. Today I got some RCA jacks for the post-pot sound mod. After I put them in and jiggled them around a bit to get rid of a bit of a grounding issue, which may have also been a problem with my stereo, it sounds great. I close it up and it still sounds great but the buttons wont work right. In LSDJ I can start the track with start. The D pad doesn't do anything except for when I press "right" it acts like I am also holding "a" and advances to the next pattern. Also, if i hold "select" I can move to the screen above by pressing the "up" button. Once there I cannot navigate with the d pad, it again only acts like I am holding "a" when I press "right" so I can only increase the tempo of the track. If I tap "a" repeatedly it seems to randomize the value for the song tempo. When I open the case this stops happening. So, easy fix, right? Well I have opened it up, moved the wires around to where it stops happening then closed it up again probably 10 times now and every time I close it up this happens. It seems to me that it has to be a contact issue but I can't for the life of me what I am hitting that could be the issue. Maybe I'm putting pressure on the buttons in some way but the wires are not near them. Does anyone have any idea what I could look for that might be causing this issue? A specific component to work my wires away from, perhaps? Please help. Thanks.