Suicide screen after installing SuperBIOS and removing battery.

[Killingbeans]

Okay so,

I have managed to flash a 29F400 with the custom SuperBIOS and I have replaced the original chip with the new one.

Problem is that now I'm just getting suicide garbage on the screen

I removed the battery after installing the new BIOS, but did doing things in that order actually just kill the newly installed SuperBIOS?

Or do I just have my chubby little ESD riddled fingers to blame?

 

[Mitsurugi-w]

Could just be a dirty cart connector or bad solder job (solder bridge, etc)

 

[Killingbeans]

The connector should be fine. The donor game worked perfectly before I did the BIOS swap.

I've reflowed all pins on the BIOS several times... no dice.

It has most likely been fried by ESD while I was handeling it

Oh well, at least I'll get to dust off my SMD soldering skills a bit more.

 

[Mitsurugi-w]

Got pics?

 

[Killingbeans]

I'll post a few tomorrow when I get the time for it

 

[xodaraP]

Is this a similar situation to CPS2 where the encrypted code needs to be completely erased from resident memory?

 

[Killingbeans]

Are there any specific steps that needs to be taken, when doing this conversion? I haven't been able to finde any useful information about the procedure anywhere, so I'm just sort of winging it


Anywho, here's some pics:

 

[Killingbeans]

The soldering looks like crap by now, but that's a result of the many reflows. Should still be good though.

 

[Mitsurugi-w]

You definitely need to scrub the cart edge connector. I clean all of mine with a bit of Brasso.

You downloaded the bios file from here?

 

[XeD]

wrong flash? Og are 29f400T. You have a 29f400B. Not sure what the difference between top and bottom boot is.

 

[Mitsurugi-w]

That flash should be ok.

 

[Killingbeans]

You definitely need to scrub the cart edge connector. I clean all of mine with a bit of Brasso.

You downloaded the bios file from here?

I gave it a good rub with a soft eraser earlier. Not a big fan of Brasso on edge connectors.

Yep, downloaded the BIOS from here

 

[kuze]

Check the pins on the SH2, some of those look a bit suspect in your pic.

 

[Killingbeans]

The pins on the SH2 should be good. I haven't touched those.

But...

Now I removed the 29F400 again, and of course I managed to rip off one to the solder pads that has a trace that goes under the chip

There's a unused spot called "U5 28F400" on the back side of the security card, am I wrong in assuming that I can simply solder on a PSOP44 chip in that place instead?

Is the little daughterboard that is glued on there a part of the suicide circuitry, and can it be removed without worries?

 

[Killingbeans]

Is the little daughterboard that is glued on there a part of the suicide circuitry, and can it be removed without worries?

Well, I can see that it's also on the repro carts, so I guess the answer is 'Nope..'?

 

[XeD]

Oh no that sucks! You can solder 28F400 if you remove the 29F400. That small circuit board switch between battery and pcb power to the cpu. What trace got rip out?

Do you still have the original 29F400?

 

[Mitsurugi-w]

Yes. On the A and B carts you can solder down a psop44 instead. You cant remove the small pcb but you can move it out of the way.

 

[Killingbeans]

What trace got rip out?

The solder pad for pin 47. The 8/16-bit select pin.

Do you still have the original 29F400?

Somewhere, yes. I think. You want a dump?

Yes. On the A and B carts you can solder down a psop44 instead. You cant remove the small pcb but you can move it out of the way.

Awesome! I'll try to get me some PSOP-chips at some point, and a converter for my programmer. Probably gonna end up being way more expensive than just buying a repro cartridge

 

[XeD]

If you have your original flash try flashing that. Pin 47 goes to B3 on the edge connector. If you Are good at micro soldering you can just jumper pin 47 to the B3 via.

 

[Killingbeans]

If you have your original flash try flashing that.

I bought five new 29F400s for this project. Think I'll try with one of the extra four first

Pin 47 goes to B3 on the edge connector. If you Are good at micro soldering you can just jumper pin 47 to the B3 via.

Good idea! I'll give it a go. It would definitely save me some money