So, Me and a friend was playing MGS on the PS1 that I saved from oblivion a couple of months ago, and getting stuck right after that rookie girl seemingly got mind controlled by Psycho Mantis pretty early in the game. I don't know what the correct path is (So please don't spoil it) but we figured that we had to use the card in Snakes inventory to unluck some doors. You're supposed to press L2 to access the inventory, but it just doesn't work, not only that, switching between fists and machine guns also stopped working.

Anyone know what's up?

Samus unrelated.

Anyone?

psychoi mantis boss battle? If not, don't read it's been years since I've played it so the order of events is scrambled. 

switch controller ports. Idk how to dot hat if your playing psn network though. It makes you not be able to hit him at all until you do that.

Never heard of that before, but I've only played it once though recently. Any chance your controller is broken and/or game is messed up?

During the mantis boss where meryl is controlled you need to knock her unconcious (i think) by rolling at her or choking her out. Im not sure exactly though, been ages since i played it.

Sounds like your controller is broken.

the correct path??

idk you kind of threw me off

but are you saying that you are stuck on the Psych Mantis boss battle?? well i'll just say that Mantis can basically read your mind. He pretty much knows what buttons you are going to press on your controller as you press them.

i'll just leave it at that

if you are stuck at the boss battle... you can search the web for a solution. after the battle you don't need any card to progress because the dieing mantis opens the door for you... if that didn't happen the game did glitch on you i guess... tell us more details about the issue.

edit: just remember, that the colonel did say not to use any guns on Meryl so is normal that you cant use R2 or L2... just knock her out by pushing square near her...

Awesome battle. Enditall727 just gave you a clue of what you have to do. Or look it up on the web.

Snake uses cards automatically. If you have the right level, the door will open. It sounds like you and Meryl just busted out of the jjail cell and she has run off. You need to go down to the lowest floor and find some C4 and blow up certain walls to advance further.

Or, you just went to the room where Snake isn't allowed to use weapons and your nanomachines have taken that option away from you. We can help but your OP is really vague. Tell us exactly where you are and we'll get you on the right pah.