Restoring c-sync on a rev. 3-5 AES: I have a few questions.

I was able to get my 3-5 AES up and running again (thread here, if interested), but there are still various video issues running it through my OSSC. The first thing I'd like to clear up is the sync output from this console, since that's where I've had problems with the OSSC before and also because Neo Alec mentioned it in the previously linked thread.

I've done a bit of digging on the specifics of it, but in doing so encountered a few differing bits of information on just how to go about the process. I'll post how I intend to restore the c-sync to pin 7 on the AV multi-out and if someone 'in the know' could chime in I'd really appreciate it.

The first thing I intend to do is remove composite video on pin 7 of the DIN8 multi-out; to do this I am going to back trace from pin 7 on the PCB and de-solder whatever component bridges the connection from the rest of the board to pin 7. I don't have the console open but off the top of my head I believe it's one of a group of resistors below the DIN8.

Once that's taken care of, however, what is the appropriate pin to pull the sync from on the CXA1145 chip? In my other thread Neo Alec mentioned using the input leg (pin 10 on the CXA1145) with in-line 470ohm resistor + 220uF capacitor to attenuate. However, in other information I've unearthed, the data sheet for the CXA1145 shows pulling c-sync from c-sync out (pin 11) with an in-line 75ohm resistor + 470uF capacitor for attenuation (data sheet image here). (I imagine the data sheet assumes the SCART cable being used for the output has the resistor + capacitor installed in the connector end of the cable, but the SCART cable I'm using doesn't have this setup; it's a cable I wired for use with a NeoGeo CD with breakout stereo audio cables.)

I should probably also note that I want to keep composite video; I have RCA jacks already installed on the back of the AES and I would like to keep them functional since they're not going anywhere.

So, long post short: After removing the component that's feeding composite video to the DIN8 sync pin on a 3-5 AES, what's the best method of restoring sync signal to the DIN8?

• Is it pulling sync signal from pin 10 on the CXA1145 with 470ohm resistor + 220uF capacitor, or
• Pulling sync signal from pin 11 on the CXA1145 with 75ohm resistor + 470uF capacitor?

I've got a restock of components on the way, so I'm hoping to be able to mess around with this in the next couple of days. Any help would be greatly appreciated, and I thank you all in advance!

Csync from pin 11 is how the original model AES did it.

Try pin 11. Use the input signal on pin 10 if you have any trouble with it. I was only suggesting it in the other thread because it sounded like your encoder chip was all messed up and you weren't getting any picture.

I had to bypass the encoder for sync on my 3-4 because the Framemeister wasn't liking the sync signal from it.

Neo Alec said:

Try pin 11. Use the input signal on pin 10 if you have any trouble with it. I was only suggesting it in the other thread because it sounded like your encoder chip was all messed up and you weren't getting any picture.

I had to bypass the encoder for sync on my 3-4 because the Framemeister wasn't liking the sync signal from it.

Click to expand...

What's the proper attentuation combo for the resistor + capacitor? Or are either valid in this scenario? I have the 470ohm resistor + 220uF capacitor readily available, I'm assuming that will be fine since you mentioned it in the other thread.

I may still pull from pin 10 since pin 11 has that bridge and running multiple wires to and from it might be a bit messy to look at.

Correct. That resistor/cap combination is mentioned frequently for TTL sync online.

Go with the normal pin 11 first, and if it doesn't work, there's always the TTL sync going to pin 10.

Okay, thanks for all the feedback, I'll be getting to this project in the next few days. I'll post some results when it's all finished!

Spent a bit of time with the AES this weekend, and I got the sync issues resolved. The picture is solid and my OSSC has no problems with the signal from the AES.

https://i.imgur.com/t9BwzZP.jpg

The only issue now is the jailbars. You can't really see it in that photo, but my 3-5 has pretty pronounced vertical bars when you're looking at the image in person. So that means the next mod is going to be an RGB bypass; I found some info about using a THS7314/16 amp to handle the RGB output, so I'll be using that. Always gotta have a project, right?

Anyway, thanks for all the help in this thread, I appreciate it and I was able to tick one box on the ever-growing list!