ALL SATURN Problems Fixed

[SpaceBooger]

Bringing up an old topic... I figured out what it was - no power to the ports. I just got one of those Retro-Bit wireless Saturn pads and it didn't work - no power to the receiver. So I did some digging and came across this post about the fuse burning up on someone eles' system: https://www.reddit.com/r/consolerepair/ ... rts_found/

Sure enough, the bottom one in that pic on mine was also burnt. I touched it and it came off. So it seems that this is why I can not use anything other than the standard controllers. Now I can not figure what to do next. I may just have to get a new Saturn (one that works with my RacketBoy modchip) since I'm not sure I can replace the fuse.
Any suggestions?

[Limewater]

I'll give you $6 for your Saturn!

Really, though, why do you believe you can't replace it? Can you not figure out an appropriate replacement, or do you not trust yourself to solder on your system?

[SpaceBooger]

I'll give you $6 for your Saturn!

Really, though, why do you believe you can't replace it? Can you not figure out an appropriate replacement, or do you not trust yourself to solder on your system?

If it's a solder and replace, I'm down and will do it in a heartbeat. All over the net it seems to be that people couldn't fix it. I need someone smarter than me to tell me what to get and where to get the part.
Also it's only powered controllers that I can't use. So the standard gamepad is fine. Haven't tried the 3D analog controller yet.

[Ziggy]

Yes, the repair would be to desolder (what's left of) the damaged components and then resolder replacements. You would want to verify that the related pads and traces have not been damaged. Remove the damaged components and clean up the mess with isopropyl alcohol. Use the continuity setting on a multimeter to test the pads and traces. Then solder in the new components.

If your resistor isn't blown up, you can verify that it's still working with a multimeter. Just the resistance across it. The reading wont be accurate because it's in circuit, but if you get a reading at all that means it hasn't been blown up. No reading, then it's damaged. There should be a number code on the resistor, you can Google it to see what value it is. Whatever reading you get on your multimeter (again, wont be accurate because it's in circuit) should at least be in the ballpark.

The parts are easy to get from a place like DigiKey or Mouser. They're surface mounted and the package is probably 0805, although I'm just taking a stab in the dark since it's impossible to tell from a pic. You can figure out the package size with a digital caliper. If you don't have one, a cheap one will be worth every penny.

https://www.amazon.com/Digital-Caliper- ... r_1_3?th=1

Even if a cheap one doesn't have NASA grade accuracy, it will be more than accurate enough for this kind of thing. I have a couple of more expensive calipers, but I have that exact cheap set linked above that I use often and it's been great.

https://www.digikey.com/en/products/fil ... Nc6ACZMxQA

As for the values, according to the reddit post no values are listed for those components in the known schematics. FB11 I'm guessing is a ferrite bead. Usually fuses are are marked just "F" while "FB" is ferrite bead. That said, I have no idea how to determine the value. Knowing that it's 5v, it may be possible to make an educated guess on what a safe value to get would be. Obviously Sega didn't choose the correct value, perhaps the current rating was too low. But if you choose a FB with too high of a current and resistance rating, that may negatively impact the 5v line.

[Limewater]

If you have it open, can you post a pic or two of the PCB around that area on your own Saturn rather than just the one posted to Reddit? A clearer view and a little more context than that highly-cropped image might help.

FB11 wasn't on this schematic:
https://gamesx.com/wiki/lib/exe/fetch.p ... matics.pdf

But it looks like most/all of the other FB components are just 0-ohm resistors.

Also, I concur with Ziggy's post.

[marurun]

A picture from an undamaged mobo might give us part info

[Limewater]

Further update,

More confident that it's a ferrite bead. I just checked with an engineer with infinitely more digital board design experience than myself. We tend to use the inductor symbol for a ferrite, but a resistor symbol would be appropriate and is probably more appropriate.

HOWEVER, he also said that most likely there is a short elsewhere that caused the ferrite to blow, so replacing it will be unlikely to be the fix.

I don't see FB11 on the main schematic. Is this actually on a daughter board?

[SpaceBooger]

I'll t it apart this weekend and take pics of my board. It's a model 2 mk-8000a. There is one main board, a sperate board for both the CD and PSU.
Not my image but this looked like the MB in mine.

Only connectors are the PSU on the left and the ribbon slot for CD (where my modchip is) on the right.
I'll look and take pics this weekend.

[Ziggy]

HOWEVER, he also said that most likely there is a short elsewhere that caused the ferrite to blow, so replacing it will be unlikely to be the fix.

Good call !

So after removing the damaged ferrite bead and cleaning up the PCB with alcohol, then checking to make sure the traces aren't damaged, you can use a multimeter in the continuity setting to check for shorts. I would check both sides of that resistor and both pads of the ferrite bead against ground and the power rails. I think that would be a good place to start.

By the way, when taking apart a console it's a good idea to unplug it and then put the power switch in the ON position to help drain any residual power that might be built up inside. Once you go poking around with multimeter probes, you could easily short something. Specifically with the SNES, it's really easy to blow the fuse when poking around even when the console is unplugged. But it's just good practice to do this with any kind of electronics.

[Limewater]

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?