ALL SATURN Problems Fixed

[SpaceBooger]

I'll t it apart this weekend and take pics of my board. It's a model 2 mk-8000a.

When you do, can you try to get better images of the PCB around the control ports? The big image you posted is good, but I think a clearer view of everything behind all the black plastic around the ports might help. Also, it looks like there should be a decent number of test points around there.

Also, have you tried a powered controller in the second port? Does it behave any differently?

The RetroBit wireless does not work in either port - the LED barely glows and the receiver and controller won't sync.
Light Guns though won't work in Port 1, but if a regular controller is in Port 2 the gun in Port 1 will work. I have not tried a Light Gun in both ports. This working only if another controller is in the second port is what led me to believe that it could be a resistor issue where the other controller rebalances what the burnt resistor did.

[SpaceBooger]

Update: I never took it apart last weekend. Two of my kids tested positive for COVID. I am able to go to school and teach, but my wife had to stay home with the five kids to take care of the ill and keep everyone not sick caught up with school work.
I will dig into this a bit now that everyone is better again and I have time off of work.

[Limewater]

The RetroBit wireless does not work in either port - the LED barely glows and the receiver and controller won't sync.

When you say the LED barely glows, are you saying that it lights up, but dimly, or does it occasionally flicker on when you press buttons?

I don't have a Retrobit. How did the light behave when it was working normally?

[SpaceBooger]

The RetroBit wireless does not work in either port - the LED barely glows and the receiver and controller won't sync.

When you say the LED barely glows, are you saying that it lights up, but dimly, or does it occasionally flicker on when you press buttons?

I don't have a Retrobit. How did the light behave when it was working normally?

So there is a LED on both the receiver and the controller. Everything on the controller is all good. The receiver is the issue. The LED is getting low power and barely visible. It is blinking but the power is not strong enough to sync. I have the RetroBit Genesis 2.4 wireless controller to compare it to and the LED on that is bright, not dull.

The new thing, I tried a used regular Saturn Pad, the new one made also by RetroBit, and that regular controller did not work. I do not know if it was because I bought it used and it was returned broken or if the power issue had something to do with it. Needless to say, the regular Model 2 controller that came with the system is working just fine while I play this month's together retro game.

Lastly, I tried the official 3D analog pad and it did not work either.

BUT, if I plug the official controller into port 2, the 3D Pad and the regular Retrobit pad work in port 1. No workaround seems to give enough power for the 2.4 wireless one.

[Limewater]

Do you remember what controller you had plugged in or had last used when you noticed that port 1 was not working properly? It is possible that a problem with that controller caused the issue that you are dealing with now.

At this point, I believe that FB11 marked on the board is likely a misprint in the silkscreen. I haven't seen an FB11 on either Saturn schematic I have been able to find. However, I have been able to find an FB10 that I would expect to be located very close to the Player 1 Control Port and very close to the other components I could see labels for in the photos you linked. I should mention the possibility as well that it's just a difference in schematics revision.

But, on each controller port, there is a ferrite bead, FB10 and FB9, that connects the controller to chassis ground. A controller that shorted the +5V to ground could potentially pop that ferrite bead, causing the controller to lose ground reference and stop working. This is potentially good news if you can isolate the controller. If it is the controller you can have a bit more confidence in just replacing the ferrite instead of having to hunt for other problems on the circuit.

With that ferrite popped, your controller 1 is losing its ground reference. I am not entirely sure how plugging in a second controller would improve the situation, though, unless it's something weird, like the pressure from the second controller nudges the remainder of the ferrite in such a way as to just barely give it ground connectivity.

I am also not entirely sure what to make of the dim LED you reference. LEDs don't really dim-- they're either on or off. LEDs change intensity via duty cycle. I don't know what line that LED is on, but it could be that the receiver is barely powering on, attempting to boot, and failing, over and over again. I really have no idea.

Is it possible to boot the Saturn with the top of the motherboard exposed? If you clean off the remains of the ferrite bead, set your multimeter to current mode (mA), set each lead to each of the pads, then boot it up with a standard controller in port 1 and make note of the reading that would be interesting. You would most likely need a helper to do this safely, without risking further damage to the board.

[SpaceBooger]

I have tried 2 Stunners, a Nyko gun, and the 3D pad, these are the only controllers I had prior to this problem so one of them could be the issue, but I think they are not the cause.
This is not my original Saturn. I had a Model 1 from launch but sold that to buy this Model 2 on eBay so I could mod it with Racket's Modchip back in 2007. I noticed the problem after modding the Saturn and am not sure if I ever tried the 3D pad (not a huge fan of Nights) but I did notice the light guns didn't work back in 2007. I originally thought it was because I had a flat CRT based on what others were telling me online, including this site. I originally thought it was weird that my PS1 lightgun games worked but not the Saturn, so I ignored the problem for almost 10 years. Needless to say, after I got my new (to me) curved CRT for lightgun games I realized there was something else wrong and started this thread.
I really regret buying this Saturn. Its dirty, rust-looking corrosion on the heat/rf shield is easily seen through the vents on the bottom, and the cartridge slot is wonky - you cant push the memory cart all the way down or it won't recognize it. I have replaced the cd drive two years ago, after trying a new laser and PSU. I guess this is what I get for buying a $50 Saturn in 2007. Needless to say, I have sunk enough money into this unit that this controller port thing is so deflating.

Dealing with two of my kids catching COVID two weeks ago and now trying to get everything ready for the holiday, I haven't had much time to take it apart and tinker. Next week I should have time, assuming I don't get called in for jury duty (yes I have jury duty the week between the two holidays) to take it apart and get some real pics of my board. I am also not really fluent in using a multimeter. I only solder when I have clear directions such as installing modchips or screens into game boys. I would like to keep playing with this since it may be more economical than buying a new one... so I will try anything suggested that won't ruin it more since I can play most games on it.

[Limewater]

As a father myself, and a guy who posts questions about projects he doesn't actually have time to work on, I can absolutely relate.

Since it sounds like you have good reason to suspect the mod chip...

You said it was a model 2 Saturn. Are the model 2 instruction off of here the ones you used?
https://www.racketboy.com/saturn-modchi ... lation.htm

When you get a chance to take the Saturn apart, it would also be good to get some pictures of the mod chip installation, particularly anywhere you used a soldering iron.

It's kind of unfortunate that one end of that ferrite goes to chassis ground. That will make it more difficult to desolder, because the ground plane acts like a huge heat sink. That means that it will take a lot longer and a hotter iron to flow the solder on that end, and it increases the probability that you'll accidentally lift the pad off the board. You really don't want to do this.

I can give you some desoldering advice when the time comes.

At this point I would suggest opening it up and taking pictures before trying any further rework.

[SpaceBooger]

Those are the instructions I followed. I also used the AB method where I just connected those points instead of soldering the signal wire to the CD board.

So if we do determine we just need to replace that one bead. How easy and cost-effective is it? Just so I get an idea of what I may be getting into.

But, before we jump too far ahead I will get some pics after the holiday - it seems as if everything will go as planned our quarantine period ends tomorrow and we just tested everyone and all tests were negative.

Also, if I haven't mentioned it yet - thank you all for helping me through all of this.

[marurun]

Between ziggy, anapan, and now limewater, we seem to have some knowledgeable folks around here. I think that’s pretty cool.

[SpaceBooger]

So I was browsing Facebook last night and on a Saturn group I'm in someone posted an interesting Saturn they just got earlier in the month. It had a red switch on in. After taking a look at it the best guess of the group was that it was modded and had a region switch. Well, last night he decided he did not want this Saturn that he just got and offered it for cheap if anyone local would pick it up. I live 1.5 hours away and messaged him. He said the Saturn worked and he did determine that it was a region mod but had no import games to test it with. I took a chance, drove for 3 hours today, and purchased the Saturn for a crazy cheap price.

It is in fact both region modded and backup ready AND most important to me - Control Port 1 works with other controllers and light guns!

Here are some pictures (that the seller took of the unit) that I purchased:

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