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yavuzg

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Hey guys, I'm trying to repair a Naomi game cartridge for my friend. We only get a black screen when cart is inserted. One of the LCX16373 chips (16 bit latch) was getting extremely hot I replaced it. Still no joy. Checked the EPROM, it didn't checked with romident so I re-programmed it. Still black screen. My next guess is to check the flash looking mask roms on the game cart but I do not know how to read them and what would be their replacement flash chips?

The reading on the mask roms are MX28L12811TC. The datasheet says it is a 128Mbit Mask ROM operating at 3.0-3.6V in TSOP48 package

Does anybody know what would be replacement for this? If any pin compatible replacement exists?
 
Wha? You still have that rom dump? If it didn't romident with the latest mame that means it's an undumped version so send to mame.
 
What game?

Did you use a fresh chip for IC22? If it didn't verify, it may be that it was faulty as opposed to undumped. Even if it reprograms and verifies right away it might start failing again quickly.

I could be wrong but I'm farily sure IC22 contains the checksums for the other chips. If IC22 works I would think the system should at least load BIOS and you can hit test mode right away. Then run rom board test to check soldered roms.
 
Wha? You still have that rom dump? If it didn't romident with the latest mame that means it's an undumped version so send to mame.
I still have the dump but the IC was busted, even after blanked twice it cannot be re-programmed so I used a fresh eprom (27C160).

Anyway, the cart is just a JAP Gigawing 2 cart. The EPROM label has the original Sega stciker and marked as "22270". So I don't think its an undumped one...


What game?

Did you use a fresh chip for IC22? If it didn't verify, it may be that it was faulty as opposed to undumped. Even if it reprograms and verifies right away it might start failing again quickly.

I could be wrong but I'm farily sure IC22 contains the checksums for the other chips. If IC22 works I would think the system should at least load BIOS and you can hit test mode right away. Then run rom board test to check soldered roms.
Yes I used a fresh (as fresh as they are anyway - aliexpress :) ) EPROM. Still black screen... I didn't even bothered to try to press the test button anyway. I mean black screen is black screen, it wouldn't respond to anything let alone the test button, right? Before I shelve it I'll try to press the test button anyway... :)
 
Any news about an equivalent MX28L12811TC tsop48 memory type? It's a CMOS memory type or a NAND FLASH?

EDIT: maybe the S29GL128 memory type is the correct one?
 
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