If it's working for you then consider yourself lucky, as it's really a crapshoot whether the games will work together or not, especially once you start getting aftermarket carts involved. You even mentioned they crash sometimes.
3.58MHz for NTSC, 4.43MHz for PAL
Unrelated to the above crystals by the way, I prefer the slightly faster crystals to the 24 Mhz ones for better picture quality, but they will both work, and won't cause the stability issus you're having.
You can build replacement oscillators that customize to...
The "-PAL" is marked on the AC adapter, but not on the bottom of the console. After all, the console only cares what voltage it's getting, not what kind of mains you're using.
Here's an example PAL console:
https://www.neostore.com/PAL-220V-Neo-Geo-AES-console-system-boxed-p/569.htm
Again...
Wow, that sucks. It's got to be something really minor. These boards are old, but leaving them on all night shouldn't hurt anything.
I would gently re-seat the bios to start.
Per this thread
https://www.neo-geo.com/forums/index.php?threads/neo-geo-aes-pal-to-ntsc-conversion.250482/
you need to...
- Replace crystal 4.43 by 3.57
- Disconnect jumper PAL1 & PAL2
- Bridge up NTSC to pin 7 of CXA1145P
- Confirm Pin 7 is supplied with +5vdc
- cut the PAL jumper next to...
Hi there. I'm not aware of it being uncommon. I own it too. It's here on mvs-scans.com:
https://www.mvs-scans.com/index.php/Quiz_Meitantei_Neo_%26_Geo
Coincidentally, I'm doing a video on this game later this month, with a story walkthrough and question translations.