TMNT: Watchdog FTW

XianXi

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Working on a TMNT board which I think is a different style board than a normal TMNT one. It is Konami though and roms were verified.

Anyway, when I got it the thing was in watchdog.

-D6 on the 68k was registering low, everything else pulsing.
-Checked the work ram and it was showing low as well.
-Pulled the work ram and put in a socket
-Checked continuity for both work ram to 68k

Without the work ram in the socket D6 on the 68k was still grounded.

-Pulled the 68k and put in a socket
-68k socket D6 is still grounded

So something on the D6 line is grounded. Am I correct in assuming that?

I checked the schematic but it seems like it's slightly different for the board I have.

Mine is the same as pictured on crazykong:

http://www.crazykong.com/pcbs/T - Z/TMNT.pcb.html
 
Found a better CLEARER schematic.

So D6 on the 68k is connected to a few things.

-Work RAM
-Program ROMs
-LS253
-Konami 007644 Custom IC

Since I knew the Work RAM and Program ROMs were good I dismissed those.

Since the LS253s were Fujitsu I planned on replacing those anyway so I snipped the legs that were connecting to D6 and it was still grounded.

Snipped the leg on the custom and bam, no longer grounded.

So now I just need a working Konami 007644 Custom IC. It's a 22 pin DIP IC.
 
Mame says it's on a LE board and I should still have a couple of 'em with cracked hybrids. I'll check after dinner.
 
So I installed the Konami 007644 Custom IC, and now it's no longer in watchdog but it does a slower version of it. The screen is filled with text then reboots. RAM is all new so I know it isn't RAM.
 
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