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Forums " WORKSHOP" => Jeux : Pcb & Systèmes arcadiens => Discussion démarrée par: glstar le Lundi 05 Octobre 2015, 13:02:59 PM

Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: glstar le Lundi 05 Octobre 2015, 13:02:59 PM
Hi.
I have a Zero Gunner 2 cart with IC7-IC8 BAD.
Seems that the problem is related to the mpr-23687 IC4.
Since this is a masked rom, could someone tell me what i can use as replacement chip?
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: TylerDurden67 le Lundi 05 Octobre 2015, 20:55:31 PM
(http://www.onedigitallife.com/images/barack-obama-yes-we-can.jpg)
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: glstar le Lundi 05 Octobre 2015, 22:07:36 PM
Citation de: TylerDurden67 le Lundi 05 Octobre 2015, 20:55:31 PM
(http://www.onedigitallife.com/images/barack-obama-yes-we-can.jpg)
Oh well....
:)
So what can i use???
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: TylerDurden67 le Lundi 05 Octobre 2015, 22:12:29 PM
Its tsop48 128Mb,right ?
Equivalent arent plug and play,you need to modify à little bit
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: glstar le Mardi 06 Octobre 2015, 11:44:58 AM
Citation de: TylerDurden67 le Lundi 05 Octobre 2015, 22:12:29 PM
Its tsop48 128Mb,right ?
Equivalent arent plug and play,you need to modify à little bit
It should be 64mbit 48 pin tsop.
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: TylerDurden67 le Mardi 06 Octobre 2015, 21:04:59 PM
MX26L6420 are OK for that capacity.
Just be sure to add an resistor or 2 diodes in serial since mx are running at 3.3v and originals maskrom runs at 5v
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: glstar le Mercredi 07 Octobre 2015, 11:39:30 AM
This is the cart:
(http://i1372.photobucket.com/albums/ag327/glstar7/039C841E-F1BE-481F-84F7-08B787C7D770_zpsb6a9p1xg.jpg)

This is the maskrom chip that should be bad:
(http://i1372.photobucket.com/albums/ag327/glstar7/63EAA791-AFB8-4DD7-B5F7-5DDC61997442_zpszzojd1nq.jpg)

This is some measurement made on the chip:
(http://i1372.photobucket.com/albums/ag327/glstar7/049D670F-0E13-4894-9F63-3654B0F58E6A_zpsm37xsrcz.jpg)

How to check if the maskrom is really bad?
How can i read this one?
Which is the rom (or other) i can use to replace it?
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: glstar le Mercredi 07 Octobre 2015, 13:02:58 PM
Just for information...
This is what Guru tell me about this problem....

they are 128M.

there is only one equivalent.
it is OKI MR27V12800J
Titre: Sega Naomi Zero Gunner 2 Cart IC7 - IC8 BAD
Posté par: TylerDurden67 le Mercredi 07 Octobre 2015, 17:27:41 PM
Citation de: TylerDurden67 le Lundi 05 Octobre 2015, 22:12:29 PM
Its tsop48 128Mb,right ?
Equivalent arent plug and play,you need to modify à little bit
That what I was thinking about but since you told me there are 64mb.
Thanks for your information about equivalent BTW  ^-