Have you checked the crystal oscillators?
My board behaved similarly. No display, activity on the address/data lines for a few secs before stopping.
In my case, the 26.666Mhz crystal at X2 was dead. Replacing it brought everything back to life.
Reflowing the sockets, daughterboard, and ribbon connectors didn't work (neither did a good clean).
I'm pretty sure it's a bad connection between the ribbon cable and connector.
I could always get it to boot correctly when applying some pressure, but after changing out the ribbon cable a third...
Got it to work once after cleaning and reseating, but it came back again.
It works everytime if I apply pressure to the top, around 1A/1B (C0). So it's just a bad connection, will look at it closer tomorrow.
Thank you very much for the help 😊
SiQux
Hey, guys. I'm in need of some help.
After finally getting my M92 up and running (turns out X2 on the A-board was dead), I assembled this beast of a sandwich.
I have tested all the games, and they all work beautifully, except Dream Soccer '94.
The texts are (mostly) solid blocks, and some...
The CPSII multi is up and running (just need to mount the LCD screen in the case). Everything went great and it fired up on the first try on my rev. 4 board. No problems with the MVS multi as well.
Going to try the F3 multi now :D
To everyone involved with the multis, you guys are amazing :heart: