So I made a starfox 2 reproduction and followed the snesdev instructions....but when I try to play it on my Snes-101, I get a black screen and at a random interval, garbled graphics. I also did remove the header before I programmed it onto a 120F M27C801 EPROM. The rom I used was the english patch.

Heya, the only things we can tell you is to check that your rom image plays correctly and that you 1) didn't ruin any traces 2) all wires are soldered correctly per the SNESDEV site 3) no wires are loose 4) check the connectivity of the traces to the points on the board and lastly 5) did you test the game before you used it for a donor.

Besides that you are on your own.

Yeah I didn't test the game, I just realized that! Lucky I have a backup EPROM!

Per your PM, it looks like you succeeded I'm guessing. I'm glad.

It's got a gradient black screen effect now, I'm not sure what's going on. I fixed the checksum using IpsAndSum, removed the header and my soldering is correct. EDIT: I left it alone for 10 minutes and came back and the whole cartridge was really hot.

If the cartridge gets really hot, I guess you've got some nasty short somewhere. Do you have a multimeter that can check for shorts?

Odds are there's not a short, because a short would just make the cart not work. It suggests that he connected it incorrectly, leaving pins floats or hooking them up wrong.

I don't have a multi meter sadly, wish I did. I'll check on the board later today though.

As I told you before , you need to strip EVERYTHING back down and start from scratch reviewing those 5 potential issues I mentioned before. When I did mine, I found that the pressure from closing the PCB+eprom into the cart shell, broke loose numerous wires. So after I soldered them to the solder pads on the PCB, I hot glued them.

Sadly, I don't have hot glue but the wires stay down without a problem. I'll use a different PCB. UPDATE: I'll order a new M27C801 and see where it goes from there.