Does anyone have the schematics for a NES the original nintendo? I disabled
the lockout chip (CIC) by cutting pin 4 on it but now the reset switch
doesn't work anymore. I had tried to cut the traces on the pcb to start
with. I couldn't figure out why it didn't read zero to start with then I saw
there was a trace on the other side also. not thinking I cut it also. Anyhow
I guess I'm no good at cutting traces becuase it stil read 1 on the ohm
meter. I later realized my error. That circuit was no longer connected from
one side of the board to the other. I ran a pice of wire from one side to
the other to reconnect it and just cut the leg off the chip. When I bent it
up the leg broke off : ( With some very careful soldering I think I
could solder a piece of wire to it if I need to.

Anyhow a schematic might help me see what was wrong..

Thanks, Mike

Michael Kennedy wrote:


Does anyone have the schematics for a NES the original nintendo? I disabled
the lockout chip (CIC) by cutting pin 4 on it but now the reset switch
doesn't work anymore. I had tried to cut the traces on the pcb to start
with. I couldn't figure out why it didn't read zero to start with then I saw
there was a trace on the other side also. not thinking I cut it also. Anyhow
I guess I'm no good at cutting traces becuase it stil read 1 on the ohm
meter. I later realized my error. That circuit was no longer connected from
one side of the board to the other. I ran a pice of wire from one side to
the other to reconnect it and just cut the leg off the chip. When I bent it
up the leg broke off : ( With some very careful soldering I think I
could solder a piece of wire to it if I need to.

Well, I doubt you'll be able to find much on this one. The lockout chip's
operation is defined in US Patent 4,799,635, however, all the related
schematics and code is property of Nintendo (and a well-guarded secret,
I believe, or at least at one time). My guess is you cut the trace which
is actually the reset line (explaining the non-functioning reset switch),
so maybe a good bet is finding some way to repair the trace (maybe conductive
pen would be a quick-fix to see if that resolves the issue).

If you cut traces in funny places, there's a good chance that it won't work
right, unless you can figure out where the traces you cut were going and fix
it with jumpers, and yeah, a schematic would make the task easier, but I
don't think there will be one to be had on this one. Best bet will be to
try probing everything with a multimeter, maybe comparing everything to a
"known good" console.

As for the technical details on this modification, cutting pin four and
shorting to ground will work (that won't disable the reset switch), so the
creative soldering shouldn't be necessary, but it still might take some work.

--Doug Kelly
dougk at dougk-ff7 dot net

Well, I doubt you'll be able to find much on this one. The lockout chip's
operation is defined in US Patent 4,799,635, however, all the related
schematics and code is property of Nintendo (and a well-guarded secret,
I believe, or at least at one time). My guess is you cut the trace which
is actually the reset line (explaining the non-functioning reset switch),
so maybe a good bet is finding some way to repair the trace (maybe conductive
pen would be a quick-fix to see if that resolves the issue).

If you cut traces in funny places, there's a good chance that it won't work
right, unless you can figure out where the traces you cut were going and fix
it with jumpers, and yeah, a schematic would make the task easier, but I
don't think there will be one to be had on this one. Best bet will be to
try probing everything with a multimeter, maybe comparing everything to a
"known good" console.

As for the technical details on this modification, cutting pin four and
shorting to ground will work (that won't disable the reset switch), so the
creative soldering shouldn't be necessary, but it still might take some work.

--Doug Kelly
dougk at dougk-ff7 dot net


Fixing cut traces is a piece of cake, just scrape off some of the solder
mask or find an existing joint nearby on the correct trace and solder a
piece of wire wrap wire to join it.