Hi,

I'm looking for someone who knows the NES inside-out because I have a problem with some games I own.

The games are:
Double Dragon
Zelda II
Castlevania
Kung Fu
Wrath of the Black Manta

I have a PAL NES, with disabled lock-out chip so I can play imported games. I installed a brand new 72 (gold plated) pin connector and cleaned all my games thoroughly using products I purchased from the internet.

These 5 games are all US versions and have strange issues. I tested other US games on my NES and they all work perfectly.

Black Manta, freezes completly after the intro sequence.
Zelda's Title screen is messed up
The Player in kung fu doesn't move yet i'm able to defeat enemies
Double Dragons screen flickers when you move
The top of the screen in castlevania scrolls away as you move and after a while it comes back.

http://s894.photobucket.com/albums/ac146/BENVF/ I took some pictures

So my question is, are these games broken beyond repair or is there a way to fix them?

Thanks in advance

Yes, I cleaned the connectors using products I purchased on the internet (cartridge cleaning paste). But it doesn't help.

I really think these games are broken. All 5 games come from the same seller. 

There's a way around this using power supply converters and such, but it's probably not worth it.  The difference in Hz is to blame primarily.  Nothing you can do about it without purchasing some expensive converting hardware.