Help! reception went bad on an iPhone 2.0 and can't fix - do I open it up?

[Teeee]

Hi community. I've got some good answers here before so I thought I'd ask here if anyone has advice on my latest confusing problem.

I have an iPhone 2.0 - jailbroken and unlocked using the latest redsn0w guide on this website. It has horrible reception, 1 bar is the best I can get, usually no signal. My partner also has an iPhone 2.0 that is jailbroken and unlocked but this gets full signal when right next to my iPhone. When we swap SIMs it doesn't help, my iPhone always has useless reception.

I did a complete restore of my iPhone and unlocked/jailbroke it again with redsn0w, but no help. I'm now worried that it's a hardware fault... could it be the internal antenna?

Has anyone else had a similar problem? Anyone here messed around with replacing the internal antenna on an iPhone before?

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EDIT: My iPhone was apparently working okay a few weeks back before suddenly the signal/reception problem happened. It was my mum's phone at that point, although I'd unlocked it for her about a year ago using pwnage.

Have I posted this in the right forum sub-category?