SOS!! Sega Saturn Picture Roll / Sync Issues

Do you get the crazy screen even on the Action Replay? If you do, remove the CD assembly completely, pop in the cart, and boot it up. If the screen still rolls over, then the CD drive/modchip is not responsible for issues.

 

Never considered that but no, I never get a scrambled screen on the AR cart, always perfect on that screen.

 

Huh. The AR uses standard low resolution. I think it doesn't even change the resolution once. Maybe it only desyncs on resolution change?

Easy enough to test, burn this and give it a try...

 

Thanks, I'll fire it up shortly and test!

Apparently, consolegoods.co.uk have different SCART connectors in stock as well, not sure whether they'll help, I showed him the picture of mine and apparently the pin configuration is different on his. Ether that or it just has more pins...

I know that doesn't necessarily mean they're wired different though.

TEST RESULTS:

Yes it de-syncs on res change.

320x224 NI SDTV - Works

Works on all following modes then craps out on:

352x224 NI SDTV - Skewed picture

Craps out on all following video modes until it loops back round to the first video mode I listed.

 

Maybe try a capacitor across the composite line. Bit of a shot in the dark, but worth giving it a try. See thread >>here<<

 

i bourght the chip from http://www.segastyle.com/store/index.php?route=product/product&product_id=54
years ago before saturn chips when sky high prices.:thumbsup:

 

Hi mate, I'm not currently equipped to solder at the moment, this is the cable I have at the moment though...



I'm requesting purchase of a SCART lead from consolegoods since he says his are different to mine (I emailed him the pic from the first post).

Though thanks for the input as it may be valuable in future.

@ Druid - Test results are above mate, thanks!

 

OK, I found a guide for the exact same mod your machine has:
http://wolfsoft.de/wordpress/?p=373

If you still have the thing disassembled, check if pin1 is indeed lifted on the smallest chip on the board (the one with the little green wire connecting two of its pins). If that pin1 accidentally touches, well, anything, chances are you may see funky results. Pin 1 should be lifted, not touching the motherboard, and the wire soldered to the pin should lead to the wide connector between pins 3-4.
That's the ntsc/pal selector pin. With my own mod, I had a problem of jumping pictures due to the ntsc/pal line not getting a proper signal. However, it wasn't a clean rolling picture, just random jumps.

And try running the machine with the controller sub-board disconnected. If it doesn't boot any games that way, disconnect it during the startup animation. If it runs fine 100% the time with that board disconnected, then its the switchless mod that's fried somehow.

edit: for the resolution test: So all 320x modes work? Games using that resolution may be playable then. Saturn Bomberman runs in 320x224 normally, with 320x448 in the Wide Arena in multiplayer. Thing is, the Saturn has two cpu clocks, 26,8 and 28,6mhz. 320x modes work on both, 352x modes only work on the latter (using 352x modes with clock 1 = screen goes out of sync!). Could be that the machine can't switch cpu clocks? And guess what handles the clock generation: the same little chip I mentioned above...

I used a resistor there, not a cap, and in the end I had to combine csync + cvid + resistor to get rock solid CENTERED picture. In hindsight, I wonder if it wouldn't have been better to use a resistor+cap on just the csync line - cvid has those in the motherboard, but csync is sent out as-is from the console. The way I have it now, with csync+cvid combined, composite video output is lost.

and wtf @ your username

 

Sounds like you're onto something here, I'll have to disassemble again then and inspect that IC, I'll take some hi res of that chip and give it a good inspection!

The machine ran fine with the controller sub board disconnected, obviously I couldn't control or reset the console but it ran fine, region change/50 & 60hz mode change.

First pic of that chip:

8MP shot -> http://imgur.com/Vk9Hl

EDIT: 2 more shots

http://imgur.com/a/LEFPs

2nd EDIT: am I going crazy or are pins 1 and 2 soldered together there?







It states on that guide: "For correct working of the 50/60Hz you have to desolder Pin 1 and pull up pin 1 of IC20. Then wire it to GND."

 

Poke it with a scalpel or manicure scissor to see if the two pins are indeed blobbed together. That could be one possible cause. Gently scrape any dust off from the motherboard between the connectors of pin 2 and pin1. Just in case.

Also, check the underside of the controller board, to see if the mod connections are OK there.

If your previously broken games run fine with the controller board disconnected, then the fault seems to be on the switchless mod for sure.

 

Christ, this is microsurgery!

As you can see from the above pictures I can't even see pin 2 as it's covered by the ground wire, so I think poking it with anything won't establish much.

In fact, it looks like the connection between pin 2 and the board has been broken as well and lumped together with pin 1 to GND.

EDIT: yeah, I can't see a connection between pin 2 and the board...

Confirmed I think, look at this:



Pin 1 & 2 have been lifted and soldered to GND.

You reckon that's what's causing it then?

 

Some GOOD solder work there like .Guess they've never heard of solder flux.:lol:

There's one thing i don't understand about the mod in your saturn and the original german tut.Why leave the pic under the shielding,when there's plenty of space on top of the shielding ,which would let you still have access to the pic if you ever wanted to doing any ICSP .

 

You reckon a de-solder is needed here, re-establish pin 2 to the board then resolder pin 1 to GND?

Of course I'll have to purchase a fine tip soldering set + magnifier (any recommendations?), as I have all the time needed to work on it at the moment.

Oh and I never thanked you for linking to the SCART video, very informative. Of course when I did it I yanked the wire out of the back of the pin like a tit, then stuffed it back in. Mind you it worked again... :lol:

You'd have to ask Raylyd - though you'll have a job as he's now banned from the forums I think (according to a recent announcement). He performed the mod himself.

I'm not even sure buying another SCART will fix this now.

 

Cause there's not a wide enough hole on the shielding for all your crap to fit through. Cables would fit, yeah, but the whole IC may not. So unless you cut an extra hole in the shielding, you'd end up having to desolder the entire mod if you wanted to look under the shielding.

That's why my main modded machine is a VA0 20 pin machine. It uses a soft metal shielding, like the one under the machine, and it is very easy to cut off parts from it.

Pretty sure you'll need a solering set to fix this now.

But I'm not 100% sure the problem is caused by the badass soldering on the clock gen ic. Can you post pictures of where the wiring goes on the pic16 switchless mod ic? I can't clearly see one side of the pins, and where the +v and gnd pins are connected to (the rightmost upper and lower pins on your pictures). Also, post pics of the underside of the controller sub board, so we can see if there's any other solder blobs or bad connections there.

You said that the machine runs perfect with that thing removed - so, we have one 100% sure cause for a fix. Let's do some SCIENCE to narrow the problem (try each test 2-3 times, just to be sure):

- start the console with the sub board disconnected, will the game boot, if it does, will it roll the picture?
- start the console with everything connected, then disconnect the sub board during the splash animation. Will the picture roll, or is it perfect? Will it "jump" from 60 to 50 hz as you disconnect the sub board? (50/60 switch is done by the same IC, right?)
- start the console with everything connected, wait till the screen rolling starts, then disconnect the sub board: will it fix the picture?
- start the console and have the sub board disconnected in any which way that gives you good picture. Then reconnect it. Will the picture go crazy?

 

I'll need a little time on that one (supposed to be going out shortly, possibly for the evening), also do you mean I should remove the electrical tape completely from the mod and show where all the wires connect to the PIC?

I can do that and take some snaps also showing the controller board. Will update ASAP

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

Shots of the PIO Board:




Underside PIO board, showing where the two wires connect:





Image showing the modchip, I'm unable to remove all the tape due to the fact I have none myself to replace it. I'll be stocking up on supplies soon though if necessery!



Closer, showing the soldering: (I've seen the other resistor and the soldering looks clean.



Showing where the bottom right 2 pins are soldered to from the images above:



The 2 points on the underside look like clean solders, they're too awkward to take snaps of at this point.

I'm going down the 'Try another lead' method at this point before I think of purchasing a soldering kit and spend 18+ hours trying not to ruin the console. The last time I picked up a soldering iron a fire alarm went off.

As for the above tests:

• start the console with the sub board disconnected, will the game boot, if it does, will it roll the picture?
• Game boots, picture rolls
  

• start the console with everything connected, then disconnect the sub board during the splash animation. Will the picture roll, or is it perfect? Will it "jump" from 60 to 50 hz as you disconnect the sub board? (50/60 switch is done by the same IC, right?)
• Not tested yet - results to follow

• start the console with everything connected, wait till the screen rolling starts, then disconnect the sub board: will it fix the picture?
• Not tested yet - results to follow
  

• start the console and have the sub board disconnected in any which way that gives you good picture. Then reconnect it. Will the picture go crazy?
  
• Unable to test without de-soldering the mod chip from the PIO board all together as I've had the cable out and the only other thing connected is the mod chip via the solder points.

I may wait 'till tomorrow to test when the new SCART arrives as I've ordered it now. Fingers crossed it works off the bat and that was the problem from the beginning, though I don't have high hopes for it working with the new cable to be honest.

:crying::drink:

 

What the hell is that chip connected to... You can confirm that you can get a stable picture with the controller sub board ribbon disconnected, though?

 

Stable in the BIOS yeah, not game though.

The chip has 2 lines connected to the underside of the mainboard, 3 to the power on LED, 2 to the underside of the PIO board (for region & hz switch) and two wired into the mainboard just below where the mod chip is sitting (see the last pic in my last post) - all solder work looks clean for the entire job, except the small IC.

On there after having another look, it seems that the connection on pin 2 isn't broken, what I thought was the board underneath showing where pin 2 had been lifted looks in fact like oxidation of the solder.

Pin 2 however is definitely soldered to GND along with pin 1.

Another wierd thing happened today where the console will now only output composite (B&W scrambled in game) to my TV, but I put that down to the butcher job I did on the cables coming out of the back of the SCART connector. Though no matter how much I secure the connections to the pins at the back it's still composite.

I've got a new one arriving from consolegoods.co.uk should be tomorrow as it's 1st class recorded. This is apparently different to my current SCART cable, which I suspect could be a US/JP SCART. This may explain things, though we'll find out tomorrow.

Otherwise it's buy a soldering kit time at the weekend, and a grueling surgical repair job on the small IC trying to seperate pin 1 & 2 while maintaining pin 2's connection to the board and grounding pin 1 without crossing the two.

The thing is fucking tiny, so I'll need a magnifier, a daylight lamp (which I have) and A LOT of time. Not looking forward to it if that's the case.

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

I also found that IC on the schematics, not sure exactly what role pin 2 plays here though!

 

oh, I thought it gave you clear picture everywhere. Scratch the tests then, it doesn't matter.

[/quote]Another wierd thing happened today where the console will now only output composite (B&W scrambled in game) to my TV, but I put that down to the butcher job I did on the cables coming out of the back of the SCART connector. Though no matter how much I secure the connections to the pins at the back it's still composite.[/quote]
If you managed to touch the voltage pin on the scart to ground, chances are you shorted out the diode the signal comes from. Happened to me when I was first testing the scart connection. So if that happened, the only way you can get RGB now is a cable that gets the signal from the +5v pin, because the +9v output is now dead.

No, you have a scart compatible with PAL machines. However if you get a cable that uses pin 4 on the AV outputs (+5v line) instead of pin 1 (+9v on PAL, c-sync on NTSC), that cable will work on all machines equally.

That seems to be the only thing out of ordinary at this point. Other than completely removing the entire switchless mod chip, which would be a pain, and may not even fix it.

Pin 2 goes through a blob of resistors and into the SMPC (the chip that handles joystick inputs, clock, and region settings). However the line it enters is not marked on those schematics. Still, the line being replaced with GND could mess up everything else connected to those resistors (which is nearly every cpu reset line by the look of it).

 

*sigh*

No sign of the cable today, hopefully it will arrive tomorrow then.

What so I could have potentially knackered one of the diodes here:

http://i.imgur.com/0BClIh.jpg

What do I use to replace them if needs be?

Though hopefully the new cable works as it says in the description it functions on all region Saturns.

 

If the cable works on all saturns, it should use the +5v pin (I have no idea why they had to complicate this with the PAL machines).

To find what got shorted out, you'd have to trace the AV plug connections back to anything that isn't TP1, TP4, TP11 or one of the black little matchboxes. I'd guess it's that thing with 101 on top though, but it could be one of the caps behind. Can't be sure without a multimeter.