Galaxy Tab 2 P3100 4.1.2 update has broken SIM functions

My father's Galaxy Tab 2 7" automatically tried updating but failed because of slow net connection, and the SIM functions stopped working.
After many attempts I updated it through OTA to latest firmware, PDA:NA3 / PHONE:LK1 / CSC:NB1 (INU) in Kies, and the Android version is listed as 4.1.2. , but the problem still persists.

The tablet can read the SIM, as the provider specific SIM menu is available, but the signal icon shows no SIM most of the time. Upon being called, the tablet rings twice and then cuts the call off by itself, listing it as a missed call, while the caller can still hear ringing.

Any way to fix it?
I'm open to rooting too as a last resort, but the ROM must be very stable as my father isn't very tech savvy and the tab is his primary phone.

P.S. what's with Kies downloading ~1GB of update and still failing while the tab downloaded only 110 MB for update and succeeded?

Didn't get you? Finally you updated with OTA(i.e. from TAB) or via Samsung Kies?

In chronological order:

SIM functions stopped working when the tab tried to update itself through wifi.
So I tried to update via Kies but that would never finish.
Then I did it through OTA manually (by selecting software update in settings.) The update was successful. But still the tab won't show sim is inserted and calling isn't possible.

If you haven't already done, try factory reset (backup your data first).

Tried. Didn't work.

- - - Updated - - -

So what's the most stable ROM for Galaxy Tab 2? There are lots of ROMs listed on XDA forum, but I don't know which one to choose.

Installed Cyanogenmod 10.1 (JB 4.2.2) using this tutorial. Calling is working again. Stupid Samsung people.

- - - Updated - - -

The problem cropped up again. The tablet shows no signal. Even when it shows one, the signal disappears the moment you try to make a call or are about to receive one.
WHat to do?
Is this a hardware or firmware problem?

I think the issue may be related to Baseband selection. It may not be set to India specific values. I am not sure here, but I am going by the experience I have had with my Defy+. There is an app for switching baseband in Defy/Defy+ devices. Try getting a response from XDA.

Baseband version is listed as p3100ddclk1. It seems to be the official version. As I mentioned cellular functions stopped working after official update.

I've posted the question on XDA as well but haven't received any reply yet.

K

revert back to stock touchwiz rom and go to the samsung service centre,play foolish and get them to check out the sim slot imho

Fixed it. Downloaded the official rom from sammobile.com, installed acc. to instructions, wiped cache, and the problem's gone. Weird it wasn't working in CM.

The problem's back, in stock ROM. The tablet has rejected SIM in both CM and stock ROM. Anyone else experienced this?

Chetan1991 said:
The problem's back, in stock ROM. The tablet has rejected SIM in both CM and stock ROM. Anyone else experienced this?

Try service center.

They said motherboard will have to be changed, for 6k. Ridiculous. One could get a tablet as good as Tab 2 for that money.
So I'm assuming no one has experienced this problem before?

O

Try downgrading to 4.0.3 listed on sammobile, and then see if your problem still persists.