When Disabling the NES Lockout Chip Fails...

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bog7
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When Disabling the NES Lockout Chip Fails...

Post by bog7 » Fri Dec 18, 2015 11:36 pm

I have recently acquired a NES.

At first there is flashing blue screen but the games load if you jiggle around the cart and find the sweet spot then push reset.

I tested some games and most worked as long as you jiggled the cart.

I removed the 72-pin connector and adjusted any misaligned or bent pins. Afterwards, no games would work even if you jiggled them around.

I replaced the 72-pin connector with a good working OEM connector, and had the same problem.

I disabled the 4th pin on the lockout chip, now the screen doesn't flash, it is solid blue and no games work even if you jiggle them around.

Can someone offer me suggestions? I've had difficulty searching for solutions because all the results are flooded with tutorials for disabling the lockout chip.


What do you do when disabling the NES lockout chip fails?

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Memblers
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Re: When Disabling the NES Lockout Chip Fails...

Post by Memblers » Sat Dec 19, 2015 12:38 am

If the lockout chip was the problem, the game would start up normally but continually reset. So we can rule that out.

My first suggestion would be to clean the edge connector on the NES mainboard, the one the 72-pin connector slides onto. With isopropyl alcohol, or contact cleaner like DeoxIT is even better. Clean the cartridge(s) really good, too.

Be sure to take precautions against electrostatic discharge, touch unpainted metal before handling the board. How problematic this is seems to vary widely between different people, I know some people who (audibly) zap things all day, while I'm fairly lucky that it only happens to me in extreme cases (like getting out of the car then touching the door on a dry winter day), and I handle bare boards all day at work. But ESD can destroy a chip without it being felt on your fingertip or being heard.

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MottZilla
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Re: When Disabling the NES Lockout Chip Fails...

Post by MottZilla » Sun Dec 20, 2015 4:09 pm

Maybe the problem isn't just the connector and your games need cleaning.

Or maybe it's another failure somewhere. Bad power supply? Bad regulator?

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bog7
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Re: When Disabling the NES Lockout Chip Fails...

Post by bog7 » Tue Dec 22, 2015 9:56 am

Thanks for the responses, although the first one got me stressed out for no reason.

The problem with the system is the connector, it's slightly curved causing the edges not to connect properly.

Cleaning the games thoroughly did help.

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