PS2 not working with OSSC

[vrooze]

Hi All,

I’m having a bit of a nightmare!

 

Been getting back into the PS2 a bit recently and forked out the cash for a 1.8 OSSC.

Arrived. Hooked up, didn’t work.
Updated fw to 1.09 (shipped with 1.07). Didn’t change.
Bought another cable with combined  component and composite outputs. Didn’t work BUT I did notice something weird.

I know PS2 syncs on green. So I unplugged the green and plugged in the yellow composite and it fired up and synced at 625-i, albeit with messed up colours.

Removed the other 2 cables and the resulting image is greyscale (this might to be expected).

When first powering it on and selecting AV2 modes. It behaves the same as this post: https://videogameperfection.com/forums/topic/ossc-worked-perfect-for-two-days-now-malfunctioning/

I suspect this is the box scanning for a signal rather than glitching out.

Now I have 2 suspicions.  Either the console isn’t outputting green correctly (it _is_ outputting something as swapping the cables around the green cable changes the output when swapped with red or blue)

Or the OSSC isn’t able to pick up the green signal well enough but can the composite.

 

I’ve tested this with 2 different cables and the issue is the same. only with the composite yellow in the green port will it sync.

 

I’ve tested RGB and YPbPr. My TV and two desktop monitors.

 

Any advice would be very appreciated!

[marqs]

I’ve tested RGB and YPbPr

You refer to the mode selected in PS2 system menu, right? Aside from 480p/HD output modes, PS2 embeds sync on Y/G channel only in YPbPr mode. If YPbPr is selected and OSSC still reports “no sync”, try adjusting Sync opt -> Analog sync Vth.

[vrooze]

You refer to the mode selected in PS2 system menu, right?

Yessir!

If I whack the green back into the RCA and adjust Analog sync Vth. I can get all the way up to 349mV and nothing happens 🙁

 

edit:

 

Ok the LCD reports a bunch more “scanning” behaviour when upped to 349mV but still no sync

• This reply was modified 1 year, 1 month ago by vrooze.

[vrooze]

Think I may have worked out whats wrong. There’s a Messiah (1) modchip fitted I wasn’t aware of with loose wires due to the age. I’m going to desolder that as I don’t need it any more and try again!

[vrooze]

Nope. Chip removed. No change

Sad panda…

[marqs]

Is there any way you can try hooking the Y/G wire into AV1 sync (e.g. via composite scart adapter)? That could rule out a hardware issue (e.g. missing termination) on AV2.

[vrooze]

Interesting development.

I borrowed a friends slim ps2. Worked instantly.

Curiously while having the composite hooked to green. And using AV2 RGB upon setting the console to YPbPr the screen turns green. While nothing changes on mine

 

This leads me to believe component output is non functioning on my console. Do you have any pointers where to look? I already removed the Messiah modchip so I’m wondering if a track has been cut or component removed etc…

Sigh. This was supposed to be a fun retro memory thing not pc debugging lol

[marqs]

I’d consider getting a RGB cable if sync on Y/G is intentionally or accidentally disabled on the machine you have.

[vrooze]

I’m still morbidly curious HOW the YPrPb is disabled. I inspected the board and there are no visible cut tracks, bridged pins (due to poor modchip installed) etc.

All I can think of is some damaged components on the lines but that’s above my skillset!

• This reply was modified 1 year, 1 month ago by vrooze.

[Zacabeb]

If it’s the first version of the PS2 (SCPH-3900x), they had two companion ICs for video encoding aside from the video DAC built into the GS. One was for encoding CVBS and Y/C off digital digital data from the GS, the other for conditioning all six signals for output. I’m just speculating, but it’s possible the latter IC was responsible for converting RGB to YPbPr in the analog domain and doesn’t receive the instruction to do so. If it’s a later version PS2, all video encoding was consolidated into a single IC and conversion would most likely be done in the digital domain.

Maybe there’s been additional modding done to brute force the PS2 into outputting RGB since it would normally be switched into YPbPr when playing DVD Video in order to be able apply analog copy protection to the Y signal, breaking RGB SCART compatibility in that case. Getting RGB when playing DVD Video required either a CD with a hack or a hardware modification depending on the hardware revision, so maybe that’s what happened at some point.

[vrooze]

It’s one of the very early ones. SCPH-30003 with a tiny Square mobo (https://www.psdevwiki.com/ps2/Motherboards#GH-006_+_GD-013) but mines an N1.

It “did” have a Messiah modchip with a couple of loose wires I carefully removed to no avail.

 

*edit* I just re-read the article I posted. I wonder if the “daughter card” has been messed with as I didn’t pull that  out…

 

 

Just to update too. I bought a 2nd hand NTSC-J console and that works perfectly. It jitters at 4x but that’s to do with it being Bob.

Now I need to learn how to set up the OSSC to the best quality and stuff (and side project to see if I can get component working on my PAL one!).

 

Cheers!

• This reply was modified 1 year, 1 month ago by vrooze.

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