Hi All,

I have a NES which is giving me a solid gray screen.

It didnt always give me a flashing red light, just a gray screen.

I have looked around online and have done the following:
-Cleaned the original 72 pin connector (no change)
-Replaced 72 pin connector with a brand new one
-Cleaned the motherboard where the 72 pin connector goes with 90% Iso and a toothbrush
-Clipped the lock out chip
-Cleaned connectors on all my games with a q tip and 90% iso alcohol
-Giving the game a wiggle

I still get a solid gray screen 99% of the time (i know it wont blink now as I have cut the lock out chip but it wasnt really blinkg much before I clipped it).

Occasionally it will boot up a game (i mean VERY occasionally).

I have since bought another NES from ebay and this works fine with all my games so I know the games arnt the issue.

I really dont know what else I can try! Could it be the NES is at a point of no repair?

Anyone have any ideas?

TJ

The solid grey screen is exactly what you should get if the games won't boot/no game inserted. It has to be in the connection between the cart and chips. It sounds like you have done everything properly, so either you are still having connector issues or the problem could lie on the board. It's possible that through your disassembly you may have introduced a hair line fracture in the board that is causing one of the traces not to connect consistently. You could verify that with a multimeter.

swap the connector on your second NES (the one that works) with the one that doesn't.
If it works then you may have just gotten a repo connector or a dodgy one and another new one will fix the problem.
If it doesn't, you know the problem lies with the board.
This is what I would do.
If it didn't work at all I would lean towards something else being fried,
but because you say it works 1% of the time, you need to troubleshoot it with other working components.
The working pin connector would be the first thing I'd try.
Keep us posted with the results

Thanks for the advice so far!

Holy-SNES, good idea switching the working connector, I will gave that a try and keep my fingers crossed!

I have a horrible feeling it will turn out to be the board only because I seem to get the same result from the original connector and the new connector.

I have one NES console that the 72 pin connector is slightly to the side in the cart slot. Whenever I insert game carts, I always have to make certain they are pushed all the way to the left side of the cartridge tray or else the pins don't line up correctly and I get the gray screen. You might try pushing your games to either the left or right side in that console and it just might solve the problem, or else take it back apart and try to nudge the 72 pin connector left or right where it plugs to the main board to fix the issue completely.

Did you just clip the 4th pin on lockout or did you solder it to ground as well? I hear it makes a difference but I've never had to do it.

Check for bad solder points, it's not common but can happen. You might be able to see fractures in the board if you look hard enough but it's not always that easy. If you're ok with soldering you could probably remake a connection by scraping some of the green laminate off of the board and soldering a bridge wire. At your own risk.

I have to be the idiot to ask but you are cleaning the games prior to testing too right?

There is some adjustment you can do with the cartridge carrier, and as mentioned above it is possible to have it aligned poorly. To rule this out you can always try to get the cart working without the carrier installed.

Thanks for all the great suggestions! I had to work late today so havnt had a chance to try them out yet, but tomorrow will hopefully be the day my old nes comes back to life with all your help!

If it turns out that its the connector that is faulty, instead of buying a new one, just boil it for 5 minute, insert a cart and remove it 20 times (to clean the connector) and boil it another 5 minutes. Then let it dry and bend up the bottom row of pins (you could try the top row too, but its hard, no way to really get back there) with a needle or toothpick. Did that for 3-4 of my 72-pins connector and they all work flawlessly-ish, most game I don't even have to push down for them to work as they fit tight just pushing em in.

ITS ALIVE!

So I opened it back up, removed the shield and the cart tray and moved the 72 pin connector around. left, right, back, forward a few times, then put a game in and kept moving the connector and testing it, eventually it recognized there was a game! Kept trying more games, all working. So I just put the pieces back 1 by 1 testing after each piece with success!

I dont know exactly what fixed it, maybe the 72 pin connector was not aligned right or maybe the moving it around scraped more dirt off, but it works

Thanks for all the help and suggestions. Im so happy to get this working again, its my original one from when I was a kid so has a bit of sentimental value to me! Its now back as my main console.

Glad you got it going