After Cleaning Logic Board With Isopropyl Alcohol iPhone Still Loops

Hi guys!

Well I have an iphone 4 that is damaged by water. I desembled the phone and put the logic board for like 15 minutes in isopropyl alcohol. Then I took it out and brushed the pins and connectors with a tooth brush.

There were several conectors with corrosion, which disappeared I think like 95% of it. One of the connectors was the one where the LCD goes and the one where the camera goes. But I brushed all connectors anyway just to make sure it was clean.

I waited for one night, and the next day when I assembled the phone, it still loops in apple logo.

I checked the battery with a different iphone 4 and it works. So I know the battery is not the problem. I also tried the good battery from other phone in this one, and the phone still loops in the apple logo.

Could this be that I need to clean the logic board more? What could be the problem? I believe it is pretty much clean, but maybe I need to clean it a few times more?

Do you think it's a logic board problem? I don't really know what else to do except re-clean the logic board with alcohol.

Any suggestions are welcome. Thank you so much!

EDIT: When connecting iphone to the computer it stayed like 10 minutes with the apple logo on. Not looping. Then the computer detected the phone and installed drivers, but nothing changed in the iphone. I opened itunes and it detected the phone but said that it could not read any of its content and I had to restore it. So i did. It has IOS 6.1.3. When it was restonring the screen of the iphone has horizontal - 1 pixel thin - lines all over the screen. After a while itunes gave me a 1602 error and now again itunes doesn't detect it.

What does this mean? Can the phone still work? It's a good thing that itunes detected it, right? However I can't seem to make itunes detect it again. =/