Hi all
So Ibought this iPhone 4 to repair, the screen was cracked and it didnt powered on, I replaced the screen and put it back together, connected to a charger it just shows emergency call, on info it says ICCID & IMEI unknown, in that screen it also shows the itunes logo for restore
If I connect it to the PC it hangs in a boot loop, I have tried restoring it with custom firmware 5.0.1, and 4.3.5 during pwned DFU mode, redsno0w cant jailbreak it, I have searched everywhere, I dont have SHSH or any other iformation as tiny umbrella doesnt show info of the phone
Can anyone please help me
Thanks in advance

This phone is likely pretty much destroyed. The blank IMEI and ICCID means that the baseband is likely bricked, so the phone will not complete a restore (unless you make a custom firmware and remove the baseband) until you either replace the baseband or the main logic board. Aside from that, if the baseband IS bricked, even if you complete the restore it will fail to completely boot, it will kick into recovery mode again.

:O
Is there a way to do so??...How can i remove the baseband or even replace it to make it work?
Is the only way to fix it to replace the complete motherboard?

There are two options. The cheaper but harder option is to actually buy a replacement baseband chip and replace the chip on the board. This will require some specific tools -- you'll need at bare minimum a very good, fine tipped soldering iron. In a perfect world you'd also have a solder sucker to help remove any excess. I don't recommend this type of fix if you're not already familiar with soldering and engineering of this capacity, it's a hard thing to get right unless you've got a lot of experience.

The easier but more expensive option would be to buy a replacement logic board, however, this is still not an easy replacement. Though it won't require soldering, there are a lot of very breakable cable receptacles and things, so be very careful while doing it.

Either of those two things should fix the phone for you. You won't be able to just remove the baseband, you will end up with the same situation you're in now, the phone won't be able to flash and even if you remove the baseband firmware from the .IPSW, when the restore finishes and the phone attempts to boot, it will panic because the baseband is non responsive.

So, would this service work then? They replace my baseband chip even with an unlock able bb the 4.10
Would you advise me to go ahead with this guys, they seem like a formal business
Store | BeijingiPhoneRepair.com

I can't advise for or against them, I've never used them before. I've seen people use them successfully before, but I've got no vested interest for or against them. As always, I recommend people be careful when they're shipping expensive electronics all over the world for repair -- but I'm always overly cautious. To your point, they seem to be quite a legitimate business, and doing a quick google search nets happy people posting about their experiences. You'd probably be fine.

Disclaimer: If you send your phone there and they break it into pieces and send it back to you broken, I nor the forums are responsible for it.