Not working nes

[Guest]

So I have a old original nes that does not work. I first tried it out and sometimes it would work (the game would show on the tv)when you push down the cartridge or sometimes it would work on its own. Other times when you pushed down the cartridge it did not work. I bought a new pin connector to try to fix it but it still didn’t really work. I know it is not the games bc I tried a lot of games. How can I fix it?

[PlayStation 2]

The cartridges themselves could potentially use some cleaning. Use some q-tips and at least 70% isopropyl alcohol to clean the contacts of them and see if that changes anything. 

Also, if it's possible, look into one of the mods that don't make you push the cartridge down into the system, but rather one that just lets you push it straight in.