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Hi,
I got my hands on a faulty Sega Mega Play motherboard.
I'm pretty sure the custom chip 315-5433 (I/O chip) is faulty since a couple of data lines connected to it are stuck at a weird level (stable ~2.5V) when others are either low (0V) or high (5V).
I've pulled all other components connected on the same data bus (Z80 CPU, two RAMs, one LS745 buffer) and problem is still present.

I know this chip can be found in some Megadrive 1/Genesis 1 consoles with the TMSS message on boot up:
https://segaretro.org/TradeMark_Security_System

I don't own any Megadrive with that chip, seemingly motherboards rev. VA6 are to be targeted:
https://segaretro.org/Sega_Mega_Drive/Hardware_revisions

I also don't want to buy a working console and kill it for the repair, plus I've no guarantee I'll actually end up with the right revision motherboard.

So, does anyone here have this chip I could buy from in order to complete my repair?
 
Trade ya for sys16 multi :P

I *think* one of my Japanese Mega Drive 1s has this chip, but I really don't want to destroy it as it's my only MD console and I love it, play it all the time. I'll double check tonight anyhow, make sure my memory serves me correctly.
 
Hmmmm.

I have a US "High Definition Graphics" Genesis. That guide says it should be V6. If it is, it's yours. I haven't turned it on in years and years. I have both the Mega SG coming and a Wondermega, so it'll never get used anyway.
 
Yep, mine has that I/O chip. All yours if you want it. Just shoot me a PM.
 
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Trade ya for sys16 multi :P

I *think* one of my Japanese Mega Drive 1s has this chip, but I really don't want to destroy it as it's my only MD console and I love it, play it all the time. I'll double check tonight anyhow, make sure my memory serves me correctly.
I totally understand that, Megadrive is my favourite console ever, I'd hate to kill one.

Yep, mine has that I/O chip. All yours if you want it. Just shoot me a PM.
Arg... What a dilemma, is it a worker? In fact no, don't tell me, just pull the chip. :D
 
Thanks @Hammy. @rewrite is going to send me the chip.

I had a look at that Russian site, closest they have is :

Микросхема PCS 8492 (Аналог SE-94) (QFP-160)
Мультиконтроллер
Аналог - SE-94
В чип нтегрированы TA-04 и TA-05 (контроллер джойстиков)
В американской версии GENESIS используется чип SEGA 315-5433

But it's not a 1:1 replacement for the 315-5433 chip.
 
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