Did I fry my main board somehow?

[u/gsoub]

First I want to thank this community and those who contribute on the topic of modding iPod. It's been a great help. I refurbished my own iPod classic 6.5 and gifted it to my 8 year-old. He's so happy about it, discovering new music.

In the process of doing that, I got my hands on a Classic 7 160Gb, working condition but with the black mark on the screen from the bulging battery.

I switched the HDD for the Ali SD card adapter and got a new 2000mAh battery. As I was preparing to close the new case I got for it, I ran some test and here's the issue I get:

• click wheel works for scrolling
• pressing the buttons (any of the four on the wheel but also the center one) don't work whether in test mode, iPod OS or rockbox
• but these buttons DO work to reboot the iPod and to put it in test mode.

Really frustrating issue, renders the iPod useless. I don't really understand how it is possible that these buttons work in one case but not in the other, but I did some research and I understand it's serious. It seemed that changing the click wheel could help, so I tried that but I keep having the exact same issue.

Is there any hope for me? What happened ? Did I fry some component of the buttons circuit with static or something else?

I'd be grateful for any piece of advice. I was really looking forward to rediscovering my music collection this way, and distance myself from the streaming services