Neo Geo CD Front Loader CSYNC Mod

Dr No

n00b
Joined
Sep 2, 2002
Posts
25
the OSSC is know for its "hard pixels", if you really want a smoother picture, try the RetroTink 5 Pro
Yup. I’ve been holding out for the RetroTink 4K. Hopefully not too much longer a wait.
 

LordKirkis

n00b
Joined
Oct 29, 2023
Posts
15
You can restore CSYNC on Font/Toploaders with 2 Resistors and one Cap.

Pin 10 of the CXA -> 10K R in Series, then a 1830 R to GND, from the 10K to a 470uF cap (positive leg), negative leg to Pin 7 of the AV Port.
I cut the leg of Pin 7, so I do not need to reroute the Compsite Video signal, works for Front and Toploaders.

That will yield a clean CSYNC with 0.6Vpp.
View attachment 62638

View attachment 62639

Thats the CSYNC "Mod" done to MVS btw. when consoling them or building a super gun for 75Ohm equipment (consumer TVs), take TTL CSYNC and just add attenuation.


No need for Sync On Luma at all, when there is plain old CSYNC around.
I definitely messed up the modding. My question to you is could powering the console power on in this state have caused damage to the chip or surrounding components? The game console boots, runs games, but I am seeing interference that look like scrolling, white moire pattern across most of the screen... and I also see very faint black smearing on some of the graphics that goes to the right side. I checked the voltage of the IC and all seems fine except pin 7 which is reading 4.7v when the chip info says its suppose to be 1.7. I checked some of the nearby resistors and measured in circuit with a multi meter and found that some were off tolerance by 900ohms. Thats 13% off tolerance which doesn't explain pin 7's excessive voltage. Should I be measuring off circuit? is there anywhere else I should look? Thank you and appreciate any help you can offer.72048713998__DE2A7052-1D25-4828-9640-0518153BE38C.jpeg
 
Last edited:

maki

Edo Express Delivery Guy
Joined
Jan 1, 2022
Posts
332
Last edited:
Top