Help: Need firmware for a D7100 (Can't find anywhere)

[android-uk]

Hello everyone,

I purchased this phone from China Vision for my mum. After looking at the phone its a model: D7100 (Oddly it had black tape over the model number? :/)

It was working fine before running very slowly recently, so my Dad factory reset it. It then wouldn't boot! And no backup made and no idea what the firmware was (Schoolboy error!)

I flashed this file: 6820_2.3.5_c910_tckj_tv_in_v03_root - which boots up and the phone works etc... except one serious issue.

SIM2 slot works fine, however SIM1 is not functioning correctly. It appears to detect the SIM, however it won't get a signal, regardless of SIM used.

Checking About Phone, I found the Baseband version maybe whats causing the issue! It says: DM_BASE_12A_W12.43|MTK6515_modem|11-02-2012 17:53:08

However the phone does have that type of CPU.

The software version is showing as: MTK6515_5_2.3.5_c910_tckj_tv_in_v03

Can anyone help me find a working firmware or Baseband for this device?

Chinavision are offering zero help, so I'm on my own, if I can just get SIM1 to work it be sorted.

Thank you so much. Let me know if any more info is needed