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I put the OEM chip back in and black screen...

obviously the problem is with the board. I checked the traces but no bueno.

I might as well start over. Sigh.

Yeah this thing is fucked. I give up.

Soldered in a socket and connected everything as it should be for SNROM and it's still a black screen.

Sverker wrote:This is why it is useful to keep a socketed board handy for testing your EPROMs out before committing them with solder.

That was probably my next step- I wanted to do it all in one shot though

That's odd. If Holy Diver Batman doesn't even give Morse code, then there's something seriously wrong with the wiring of A0-A11, D0-D7, or an enable. Are you sure you're using a correctly sized ROM image? (For example, use the 256 KiB image for a 27C020 or 29F020.) And are you stripping the iNES he...

had the thought to try reading the chip with my programmer after a burn to compare, but it's not that. The burn is successful and verifies with the write buffer when I read. I'm not sure where to go from here. I am hesitant on tearing the socket out and soldering it directly in...

Reprogramming should be easier than rewiring, so try flashing a few other things first: * Tepples's Holy Diver Batman! for MMC1 * Galaxian (8KiB PRG) or nocash's Magic Floor (4KiB) (just duplicate them to fill your EEPROM). Is there any chance the wires between the pcb and socket have broken? Does ...

Aaaaaand black screen. I don't know what I'm doing [wrong] but... Tried my ROM, split with TNINES 2.6 into a single PRG file. Burned ROM to EPROM just fine... No errors. Used binary format, tried fill with '00' and 'FF'. Black screen. Then tried original Rad Racer, split, burned PRG. No worky. I rec...

So you destroyed a Mega Man 2 MaskROM when removing it? Or was this Rad Racer? I asked because you said something about clipping and removing something from the holes in another step. If you desolder then the MaskROM is still useful. If you damage the legs it makes it harder to impossible to reuse....

Update- pictures!!!

http://imgur.com/a/oET0D

- The security screws were not the standard Nintendo 3.8mm variety; they were almost flatheads. Not all NES games used security screws. (In fact, my copy of Rad Racer uses the same screws as you described.) - The CHR-RAM is by NEC; 64S20 (and 8730MX) are written on the chip. This does not correspon...

So the first thing I did was take Rad Racer apart. I noticed some differences... - The security screws were not the standard Nintendo 3.8mm variety; they were almost flatheads. - The label is the North American style label with no "NES-RC-CAN" text. It seems to look USA-released. - The two...

Well don't I feel silly. I guess I'll hop to it for some new chips

Also, for clarification- modding an SGROM cart, I only need to change the PRG-ROM and not the CHR-RAM, correct?

Thank you



edit: the AT29C020 would be a 2Mbit or 256KB chip, correct? Just checking, as you typed 128

Hello new friends, I'm modifying Mega Man 2 and I have a few things I need help on. It's mainly the hardware that's giving me the uncertainty. I see that Mega Man 2 is an SGROM-02 cart, and I was planning to use Rad Racer as a donor. Rad Racer is also an SGROM-02 cart, however has only a 28-pin PRG-...