Cyvern Conversion

[Pr3tty F1y]

If you allow me a tip, on next installations use Kynar cable

Absolutely. That looks like a fantastic recommendation. Thank you!

 

[Yippikaye]

I'm trying to convert a Gals S2 (Rom-4 board) into Cyvern following the instructions.
Everything was fine until this screen where the game seems to bé stuck into.
Did I miss something ?

 

[ShootTheCore]

I'm trying to convert a Gals S2 (Rom-4 board) into Cyvern following the instructions.
Everything was fine until this screen where the game seems to bé stuck into.
Did I miss something ?

It's just BIOS code running up to that point, and then it tries to execute the code on the cartridge. Check the CPU code EPROMs located at U8 and U10. Also make sure you're running a Region Free modded BIOS on the mainboard so you don't run into any region lockout issues.

 

[Yippikaye]

CPU code EPROMs located at U8 and U10 : checked = Ok
Region free modded BIOS : checked = Ok
I'll double check the voltage regulator (5v to 3.3v) after work since last time I mesured 3.9v (I don't know why)
can someone point me to the right spots to connect my regulator to (5v and GND) ?

 

[nnap]

I usually used the decoupling caps

 

[nnap]

That wire at U10 could be relevant but I don‘t remember if this was cyvern or sengeki striker

 

[Tailsnic Retroworks]

@Yippikaye I recommend you to use AMS1117 3.3v regulator like the one in @nnap 's photo. They are sold on aliexpress

 

[Yippikaye]

Found the culprit (other than my self for a lack of quality control ) it was the eeprom in U6 (U10) a 27C801 who was faulty (I don't know for what reason since I've checked it good once after burning it)
Replaced it with a new one and my cart is working good
Thanks for the help