SOS!! Sega Saturn Picture Roll / Sync Issues

SOS!! Sega Saturn Picture Roll / Sync Issues (Pics + Vid)

Hi All,
Great site, glad to be here. I'm wondering something here, I have recently acquired a Sega Saturn (Model 1 - chipped - switchless) and have been experiencing some odd symptoms with said machine (I knew they were quirky and could be difficult, but oh my lord!).

Basically the BIOS runs absolutely fine, as does the modchip. It all works swimmingly until you try to boot a game, any game (original, burned, domestic, foreign).

Then what happens is the picture scrambles and scrolls from top to bottom rapidly meaning you can hardly make anything out. It does this on all TVs in my house apart from one Phillips 15" CRT and a Technika 19" LCD. I have 4 LCDs, on which it never works on no matter what I do.

Using the Phillips CRT I can get a stable picture after resetting the console a few times, but on the others:

Sony KDL-40EX503 - No - scrambled games (no matter what I do) - BIOS works/displays fine
Hitachi 32" LCD - No - scrambled games (no matter what I do) - BIOS works/displays fine
Bush 19" LCD - No - scrambled games (no matter what I do) - BIOS works/displays fine
ALBA 15" CRT - No - scrambled games (no matter what I do) - BIOS works/displays fine
Technika 19" - Works (only tried it once on that one though)
Phillips 15" CRT - Works after a few resets

Could this be the culprit??:


That's the SCART lead I got with it, I notice there's no composite sync pin on there and other pins seem to be missing or in different places. Ignore the shadowing on the circular end, there are no more pins apart from the ones you can see.

The below image was taken from: http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm#saturn



NOT SURE IF THAT'S THE EU PIN LAYOUT OR THE JP/US LAYOUT.

Would buying a different SCART lead resolve this problem?

Does anyone have ANY idea what's going on here? as it's driving me up the wall at the moment! I'd prefer to play this on my Sony TV in my other room as playing it on this tiny CRT is a pain in the arse.

Once the picture is stable on the Phillips then it works fine for hours, unless of course you change games then it's roulette as to whether I have to reset the console again on trying to play another game. Sometimes it changes games just fine.

The BIOS works on all TVs (CD player, stars and the little space ship ect), just not the games...

Video of the problem: (I used Play TV so the quality isn't the best!):
http://www.multiupload.com/601TZAT9K0

Changing from 50/60hz doesn't help, changing region doesn't help. The problem only occurs when playing games on all TVs.

I've had the modchip out and tried a game, same result. Though it's worth noting that the signal wire was still attached ( somewhere on the power board - not sure where) when I bypassed it. Could it be the modchip?

Thanks for reading this!

 

Based on that picture, that scart cable takes the RGB Voltage signal from pin 1 on the Saturn video out, which, depending on your model, may be either Composite Sync, or +9v dc. Composite sync is not a stable dc signal, so quite a bunch of TVs completely flip the fuck out if it is hooked up as RGB Voltage selection - they should switch to rgb back and forth nonstop in theory, but every set handles this differently so you may get just a rolling picture instead.

Regardless, measure pin 16 on the scart cable with a multimeter, if it's around ~3.3v, then it's composite sync. If it's 9v, it's a stable dc signal and the problem lies elsewhere.

You may want to open the scart connector (if it's possible), and see if the connectors are all hooked up fine. Try removing pin16 to see if you get a stable composite image. These are all the ideas from the top of my head.

 

Hi Druid, thanks for helping BTW.

I've had the SCART connector open and everything seems wired properly (no breaks - can provide pics if it'll help diagnose!). Though I don't have a multimeter or even access to one at the moment unfortunately. But if it's prudent to have one then I may consider a purchase.

 

Pictures of the scart wireup won't help much since we don't know what is wired up to what on the Saturn end. You have to manually remove/reconnect each pin one by one and see what changes on the picture.
- Removing any of the r/g/b pins should give you psychedelic colors.
- Removing an audio pin will... remove one audio channel.
- Removing pin 8 probably won't change anything (it's the aspect ratio control)
- Removing pin 16 should give you stable composite image.
The rest are ground pins, and you'd get fucked up picture or audio without that in more ways than just "rolling image".

Pretty sure it's a case of csync used as rgb voltage signal, though.

 

This is probably a dumb ass question but do I just pull at the wires with some thin nose pliers to disconnect them?

Is there any way of removing the connectors so that they can be slid back in place or do I need to cut and solder ect?



^^ Just so you can see what I'm looking at...

 

Yes, you can just pop them out and back in. That's why Scart is awesome. It has a billion uses for tinkering.
You only have to resolder if you end up breaking the connection.

Try removing pin 16 to see if you get a rock stable composite picture. If you do, the problem is the voltage in pin 16. You can either mod the console to output dc voltage on pin 1, get an RGB box that stabilizes the voltage (never used one myself, but I heard they help?), or buy a proper rgb cable (Adaptorman sells some on ebay, Consolegoods.co.uk also has good cables so I heard).

 

Well the little metal pins wouldn't pull out, just the cables from the back of them, I removed pin 16 and got composite on the BIOS but scrambled black and white in game (sega rally - UK 50hz) which is odd seeing as though it should be in colour even in composite (I would have thought!).

I removed the yellow wire by mistake and the picture went turquoise...lol

Looks like I'm going to try a cable from consolegoods.co.uk unless there are any other ideas...

 

If the composite picture is rolling as well, I'd suspect that something is wrong in the machine itself. Don't you have a normal RCA composite cable to test with?

If you disassemble the machine, do you see dust inside? I recently acquired a Saturn dirt cheap that was sold as non-working, but all I had to do was blow the dust out to get it fixed (apparently it was shorting out something on the board). Disassembling the thing may be difficult with all the mods installed, but if you can do it, look for damage on the motherboard, leaking caps, etc.

 

Disassembly shouldn't be a too much of a problem really, the mod was done very well meaning the modchip board itself interfaces directly into the FCC for the CD-ROM drive on the mainboard.

I've had the top of it off but that's about as far as I went. It wasn't bad really, a few bits, it's what could be hiding under the metal casing where the power block and CD block is which could be the key.

It's just a case of sliding it out, though I'll post some pics here ether later or tomorrow showing the model and innards as I could do with a guide to disassembly really as I don't want to inadvertently rip something out!

Do you reckon there's any chance the signal wire for the mod chip could be causing interference? I mean, if it's only crapping out when playing games then surely it has to be the modchip...

 

Obviously you can try to remove the modchip (just disconnect it from the CD board ribbon, no need to remove the power lines too), reconnect the cd ribbon, and try booting an original game. If it works that way, its the modchip.

I'm re-reading your post... with composite video only, do you get correct image + sync + color in the bios, or is it missing the color from there too? Could be that composite encoding is busted up somewhere. In that case, you could disconnect that on the motherboard and wire up pure c-sync in its place, but before doing mods that require a soldering iron, you may want to just try another cable first.

 

In composite I was getting correct image + sync + colour in the BIOS, as soon as the game booted the sync went as did the colour, but you could see the game playing, however the picture was skewed and rolling from top to bottom.

I would have thought if it was outputting PAL 50, then the colour should have remained at least, but it seems to be going into some weird video mode which isn't PAL standard I think...

If I press reset enough times I can get picture sync every so many tries, no colour though. I can only get sync on the Phillips CRT TV also.

Have you viewed the video I posted in my original post? Same as that really, except in composite mode there was no colour when the picture scrambled after BIOS, but during game.

Bypassing the modchip made no difference unfortunately..

 

Do you still get correct picture at the Sega logo, or it goes apeshit right as the game disc starts loading up?

The faulty Saturn I have locked up and started shaking the screen right as the game code started loading (immediately after the security ring check). But after blowing the dust out, the machine worked as new. Now, this still could've meant that the problem got fixed when I reconnected the cables instead of cleaning the dust. Regardless, complete disassemble and general clean-up could be an option to fix the thing.

 

I'll give that a go tomorrow then, I'll post a pic of the saturn with the lid off so you can see the exact model ect ect.

^^ Yeah, that's exactly what's happening with mine! (except the without locking up - but the screen goes apeshit)

I'll let you know how I get on tomorrow, though it may be a tall order as I only have one good hand at the moment, my left being in a wrist cast restricting my finger/thumb movement somewhat at the moment.

I may have a crack at cleaning it out later on (an hour or so). Just got to take my time as I don't want a fatality on my hands!

 

As sega ,for some unknown reason,changed the pin connection between the pal and ntsc-u/j saturns .So pin 1 is 9 Vcc on a pal saturn and composite sync on all ntsc-u/j saturns.So you have to get a scart lead to match the region of the console.Switching pins in the scart plug won't do squat .

http://nfggames.com/forum2/index.php?topic=4236.0

I (bigsanta) had to mod my white saturn a different way ,but basically it's doing the same thing as killingbeans method .

I have a video showing how you can properly remove scart pins
http://www.youtube.com/watch?v=qw0NG6QCeZo

Your connector picture (round mini din)doesn't need csync,it's using cvideo which is normal.

 

Forgot to ask,but is the saturn a jap one/american version ?If it is ,then you won't get it to work properly without either the correct scart lead or rewiring the av port inside the console!

 

He said that its a model 1 UK Saturn, so it should have +9v on pin1.

 

Yeah it's UK model 1 I think, again I'm taking pics of it as I type this to upload here to determine the model ect.

I'll also take pics as I pull it apart as I hear there are many different model types which require disassembly in a specific way.

The main thing I can't get my head round is why the BIOS works on all TVs, but not games??

----------------------------EDIT----------------------------------------

Here they are:
http://imgur.com/a/DbVfC <- Link if needed...

Is there anything I should be looking out for or anything that's pertinent to dismantling this thing. Any order needed?











Modchip:



Power board:


I can upload in hi-res if needed as well...

 

I have a similar Model 1 saturn (only the cd board is different). Getting it apart is relatively easy, you just have to watch out for the ribbon at the controller sub board. Putting the case back together is annoying cause of the plastic pointers for the LEDs. Also,

You can just unscrew it and pick it apart. Nothing special about it. (unless the modchip power cable gets in the way, but it doesn't look like it will)

Other than cleaning up the motherboard in general, I have no advice at the time. Do try making higher resolution screenshots for the main motherboard though, maybe some faults will be visible instantly.

Because the BIOS only uses some basic functions. It doesn't access some cpus, never switches the video resolution, barely sends any data to ram, etc.
So if there's a short circuit on the motherboard, for example, sitting on the line where the data loads from the CD to RAM, that could lock up the system when any data is loaded - but just in the BIOS, that line is never used, stays empty, so no short occurs and it functions fine.

 

OK, just trying to remove the power board now, the white connector seems to go down through the board into possibly the main board, do I just pull it up??



Encountering fair resistance when trying to lift...

That makes sense.

 

Unscrew the 3 screws, one on the power board, two behind it on the back on the sides of the power connector. Then just pull it off. There is resistance because the white plug pushes against the metal pins fairly hard, so the connections are safe. This wasn't the case on some Dreamcasts, which tended to randomly reset.

Don't worry much by the way. Just use common sense and you won't break anything. Saturns have a reputation for being bulletproof, not counting the laser unit. I have one that survived a lobotomy (desoldered a cpu pin by pin, then resoldered it 3-4 months later, and it still worked).