iPhone 4 After Repair Stuck on Apple Logo & Cannot Restore

Well this is not my first repair. I repair many of my own, parent's and siblings iphones. This particular iphone 4 has been in service since the iphone 4 first came out and have been running well. Of course there have been wear downs so I replaced the aux flex cable, power button and repaired the home button in the past.

So I have a lot of experience and made sure nothing wrong happened until earlier today.

The iphone was running flawless, I fixed everything except for this weird issue where the top mic wouldnt work during calls on speaker mode. It worked; however, when testing voice memo. I read online to fix this was to simply clean out the top mic hole, so i disassebled it and cleaned it and put it back together... except now its stuck on the apple logo. I thought it was fine as I could restore it. Weirdly enough I couldnt put it in DFU mode, so I put it in recovery mode to restore. It was identified in itunes but along extracting when the iphone was supposed to restart it just dies for a second and resumes frozen on the apple logo. Also strangely enough, it CANNOT run without the battery, so the only way to keep it running would have it stay plugged in. If I unplugged it it would die instantly.

So my question, is it because the battery is bad now? Does the iphone 4 not restore because it must restart for a split second, so if you had a bad battery it would cut the power during this second and not restore? Please someone help me out here.

Best Regards,

Adrian

Well I managed to fix the errors but now I have itunes error 3194. The error is related to downgrading and jailbreaking but my iphone is not jailbroken and im updating to the latest NON CUSTOM firmware.

Can anyone provide any sort of input?

I just sold the iphone 4 on craigslist. Luckily sold it for $120 for the phone only. It was the motherboard that went bad and checked on ebay. Motherboards go for $90-100+ so I was able to recover what I lost.

Oh well.