Ua-25: Noise In Left Channel. Damaged?, Damn Ebay! Options

[Bass0]

Hello everybody, this is my first post here. It's very electronics-related, so if there's anybody with knowledge in that area, your help will be appreciated. Also, sorry in advance if this question doesn't really belong here or has already been answered; I've done my best with the forum search engine, but to no avail.
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Well, the title is pretty self-explanatory. Some time ago, I've bought an Edirol UA-25 off Ebay, and there's something that bothers me. While the right analog input channel seems alright, there's a consistant noise in the left channel, and it increases by turning the gain up. I'm pretty sure the problem is hardware-related. Now, my question is, is there any way to fix it by repairing the device?

Already upon purchase, I noticed that the device had already been opened, and of course I did the same. There's a pair of relatively big capacitors (though I don't know the values) behind both analog input connectors:




On the underside of the circuit board, the soldering points of the four capacitors can be seen. You can notice that the left pair (meaning the capacitors belonging to the right input) looks burned and tampered with:




Could someone have tampered with these capacitors? I repeat, they belong to the right input, which has no noise. Maybe they've somehow been repaired/replaced? Or could this also be out of the factory?

Can I expect to get the device repaired if I have an expert replace those capacitors? Or is there some damage that I can't fix anymore?

Sorry for the long confused/confusing post, and thanks in advance!