Weird issue with iPhone - Getting stuck at boot screen

Hello, I am having some issue with my iPhone 3g. First of all, about a week ago I was having issues with my iPhone earpiece. Call volume would be too low even on max volume, almost unhearable. Since it was out of warranty barely, I had to find some 3rd party repair service. That guy replaced the whole front panel assembly, because he said he tried replacing the earpiece and the problem continued just the same.`With the new replacement panel the volume was working as good as new.

So after that, last night I had my iPhone freeze. Tried to hard reset and it got stuck on the Apple logo screen. Did a hard reset again after 10 minutes of it being stuck and it just got stuck again. So my first thing was to put it in restore mode and restore it. Got an error when the iTunes was in the preparing the firmware stage, it just got stuck there and so did the iPhone. Tried again and the same happened. Tried DFU, no luck. Decided I would open up the iPhone to see if I can see anything that was broken or anything and noticed that a piece which I found out to be the vibrate assembly moves (rotates), even with the power turned off, is that normal? It is like if the iPhone is tilted, that thing moves. Anyway, just unplugged cables 1, 2 & 3 took a look at everything. Didn't notice anything wrong except what I mentioned about the vibrate assembly, so I reconnected everthing, tried to restore again and finally it worked. I chose to restore from a backup of my previous phone.

So today, I reset the iPhone for some reason I can't remember, and get the same issue......it gets stuck in the apple logo. Tried restore mode again, no luck, again, no luck, open phone, disconnect cables 1, 2 & 3 and reconnect. Blow a little bit overt the phone and voila! I was able to restore. So I thought it might be a firmware issue, so I restore and select to setup as a new phone. Everything should be ready right? Well I start hard resetting the phone to see if it works and it restarts just fine. Do it several times and it just does fine. Then I had a phone call, reset my phone and it finally gets stuck there again! So this time I skip recovery mode, just shut off the phone, opened it, disconnected and reconnected the cable and now it works again, without even needing to restore. What could be causing this?

Thanks for your help.

 

Thanks a lot for your reply Dave. I have inspected ribbon number 3 closely and found that there is a black spot on the part of the ribbon that connects to the motherboard. Do you think this could be causing the iPhone to freeze by causing a short circuit, and by disconnecting and reattaching the issue "resets itself"?

I plan to get with this guy and getting that ribbon exchanged, he should not put stuff like that hoping that no one will notice.