# Lenovo P780 2g/3g problem



## calinmihai (Oct 14, 2013)

I have dual sim Lenovo P780.

PROBLEMS:

DEFAULT SIM SLOT (supports WCDMA and GSM) - works fine only on WCDMA /3G. When I put it on "GSM only" it goes dead - "connection error", "emergency calls only" and all that.

SECOND SIM SLOT (which is GSM only) doesn't work att all.

The sim cards are fine (checked it on other phones).
I also put other sim cards in my phone (and swich them around) => same result - sim 1 only 3G, sim 2 dead

Both of them see the providers but have no signal on gsm/2G mode.

Thanks,


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## dobranszky (Oct 31, 2013)

Same problem here?
Any workarounds yet?
Cheers


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## dubart (Dec 7, 2013)

i have the same problem and I cannot find a solution...


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## badmania98 (Jan 3, 2014)

Change radio module ( modem).


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## blur (Jan 6, 2014)

the same problem here,


badmania98 said:


> Change radio module ( modem).

Click to collapse



I cant find another one, only for S920.


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## badmania98 (Jan 6, 2014)

This is my P780 (S920, S820 are compatible) modem collection :
modem P780.zip
http://www51.zippyshare.com/v/55282913/file.html


But:
1. For Chinese model I recomend V51 or V52 ( on the battery is written in chinese). Both sims works but no WCDMA 900 band( chinese version doesnt have this frecvency) . I use V51.
2. For European model V20, V26.  (on the battery is not written in chinese). If it used on chinese model will be no signal on Sim2 (x sign)

How to install:
Download and unzip the file modem P780.zip. Chose modem file.
1. Put the modem file (zip) on the SD
2. Use CWM, TWRP or mobileUncle
3. Install modem from recovery
4. Wipe cache
5.Reboot

Let me know if it works.


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## blur (Jan 6, 2014)

badmania98 said:


> This is my P780 (S920, S820 are compatible) modem collection :
> modem P780.zip

Click to collapse



Great! Thank you.
Your zip is stored on my computer


Nothing helped, I gave all a try. 

But now I found out, thats a problem if my local provider and his radio cell.
When I leave my home cell, all is fine.


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## peteyabe (Jan 13, 2014)

I installed S920 V17 modem and both slots works for me now on my P780.


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## Wakhley (Feb 1, 2014)

*Lenovo P780 3G not working in sim1*

Hi Badmania,

I also recently bought a lenovo P780. i didnt realise it was a chinese model only after going through your post. i got a little problem with this handset and i hope u can help me out with it. Slot 1  probably supports 2g/3g connection but i am not able to get 3g connection in the slot 1. i tried swiping the same sim card in another handset of different brand and i can use 3G without any problem. slot 2 works fine with 2g.i am a newbie to this android and i dont have any idea about CWM, TWRP or mobileUncle. i would appreciate and be grateful if you could post step by step procedure to change the radio module ( modem) for Lenovo P780 chinese model. i cant read Chinese and its a big problem for me. Looking forward to hear from you soon.

Regards


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## Wakhley (Feb 1, 2014)

*Stuck Half way*

Download and unzip the file modem P780.zip, chose Modem file=  *SUCCESS *

1.Put the modem file(zip) on the SD= *SUCCESS*

2. Use CWM TWRP or Mobile Uncle=  * Downloaded mobile Uncle but cant proceed*

  Steps i took on mobile Uncle:

     1. Clicked "Into Recovery Mode" on mobile Uncle> Reboot to Recovery> OK> WARNING!! ROOT REQUEST!! > Please Root your Android First!!...............i cant proceed further from here!  PLEASE HELP ME!


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## badmania98 (Feb 1, 2014)

*Root + TWRP*

Root+ TWRP
Read me file inside.

http://www62.zippyshare.com/v/50541818/file.html


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## Wakhley (Feb 2, 2014)

*Confused*

Dear Badmania,

Thank you so much for your help and support though i couldn't execute the solutions you have provided above properly.

Finally i realized why my 3G connection on slot 1 wasn't working after doing a vast research online. I found out that, in order to use 3G  in my country(BHUTAN), i must have a smart phone that supports  GSM- 850/900/1800 MHz & WCDMA 850/1900/2100 MHz Frequencies. My network service provider told me that i wont be able to use 3G without these Frequencies in BHUTAN.

As per my knowledge, Lenovo P780(chinese model) supports GSM- 900,1800,1900; UMTS-2100 only. I am worried and confused what to do now. From where and how to add GSM- 850 MHz on this handset?????

Will i be able to solve my problem with the solutions you have provided in your previous post??? OR is there a different procedure to overcome this problem. Please help me, i like this smartphone(lenovo P780) so much that i don't want to switch on to another smartphone.

Regards,


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## badmania98 (Feb 2, 2014)

Install mobileUncle Tools from GooglePlay.
Open the program.
Under Engineer Mode\Engineer Mode (MTK)\ BandMode\ you will find Sim 1 and Sim2, where you can see what bands are availlable. GSMMode (2G) and WCDMA (3G).
 This is it. You can not add other band.
As I know, the chinese model ( mine also)has only WCDMA2100 ( on mobileUncle is WCDMA-IMT-2000). I need WCDMA -GSM 900 but ...it is not possible. It is not a software but hardware issue.
There are 2 versions of P780. One with 4G storage with WCDMA 2100, and one with 8G storage with WCDMA 900&2100 .


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## Wakhley (Feb 3, 2014)

*Thank you!*

Thanks a lot, Now i regret buying this phone to be used in my country!


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## cezar333 (Mar 12, 2014)

*Please help*

i have install root acces on my chinese p780

But i have problem when i try to install v51 modem for my sim card 2 to work in romania.

i have installed twrp manager and granted super user acces.

on my sd card i put the V51+s820.zip file 

When i enter TWRP manager / INSTALL / External SDcard / select V51+s820.zip  and then when i slide to install the device rebot into Android system recovery 3e and i dont know what to chose... i chose apply update from sdcard and sdcard2 then the android logo of installing apear for 1-3 minute (and i dont see anthing installing) and then the decive reebots.

Please help.. i dont know how o do it..


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## badmania98 (Mar 15, 2014)

You already have the answer with what you do wrong, on the romanian forum.


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## danka90 (Mar 20, 2014)

*install modem driver to P780*

Hello!

I need some help. I've bought a Lenovo P780 phone and when I put in my SIM, I realized there is no signal and the phone can't connect to the network. After some advices I tried to install modem drivers. I downloaded the drivers from badmania98's upload. I copied them to the phone internal memory (tried with SD card too, with no result). I started TWPR manager (tried with mobileuncle too), pressed install, selected one of the unzipped pack, eg. v52 Modem_P780_V52.zip. Slide the slider, my phone reboot, I got the system recovery. I choose apply update from sdcard (or sdcard2 from external SD card) and choose my zip file. My output is: 
-- Install /sdcard ...
Installation aborted.

Neither of zips work. What should I try? Did I miss something?

Thanks
Daniel


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## Moisesm7 (May 4, 2014)

*I need some assistance please.*

Hello badmania I am in need of some assistance from you please. I bought my Lenovo P780 and as I've seen and heard, people are having bad signal quality. I was looking online trying to see if there was a way to solve this problem. I ended up on this website and saw your steps on how to do it, but honestly I have no idea what I'm doing. I was wondering if you could sort of guide me through the process please. I would really appreciate it.

Thanks,


Moises


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## nandude (May 26, 2014)

Hey. I have the same kind of problem (chinese Lenovo P780, trying to use it in Hungary with a GSM 900 / 1800 provider) but the weird thing is that the phone loses signal occasionally. I mean if I check the phone, about 7 times of 10 there is no signal. I tried out a lot of modems (found on a russian blog) then I tried out the modems posted in here, but it's still the same. I checked the settings in engineer mode and everything is turned on. Please tell me what is going on.


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## Jackal331 (May 27, 2014)

nandude said:


> Hey. I have the same kind of problem (chinese Lenovo P780, trying to use it in Hungary with a GSM 900 / 1800 provider) but the weird thing is that the phone loses signal occasionally. I mean if I check the phone, about 7 times of 10 there is no signal. I tried out a lot of modems (found on a russian blog) then I tried out the modems posted in here, but it's still the same. I checked the settings in engineer mode and everything is turned on. Please tell me what is going on.

Click to collapse



I have the same problem I'm sending the phone back to the store and asking for a replacement.

I had another P780 2 months back (dropped into water} and there was no such problem.


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## calinmihai (Oct 14, 2013)

I have dual sim Lenovo P780.

PROBLEMS:

DEFAULT SIM SLOT (supports WCDMA and GSM) - works fine only on WCDMA /3G. When I put it on "GSM only" it goes dead - "connection error", "emergency calls only" and all that.

SECOND SIM SLOT (which is GSM only) doesn't work att all.

The sim cards are fine (checked it on other phones).
I also put other sim cards in my phone (and swich them around) => same result - sim 1 only 3G, sim 2 dead

Both of them see the providers but have no signal on gsm/2G mode.

Thanks,


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## nandude (May 27, 2014)

Jackal331 said:


> I have the same problem I'm sending the phone back to the store and asking for a replacement.
> 
> I had another P780 2 months back (dropped into water} and there was no such problem.

Click to collapse



Actually in my case I found out that my provider, T-mobile has some trouble with their service. I checked their Facebook page and it was full of messages by users saying that they have no signal. So I can't do anything, just wait.


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## Dark_Horse (Jul 25, 2014)

When I got my Chinese 4GB P780, it had the v51 baseband modem installed on firmmware 119 ROW. Under Mobileuncle Tools engineer mode, for SIM 1, only *WCDMA-IMT-2000* was available and enabled in the UMTS list which means there was no 3G availabe on the 900MHz band.

However, once I installed stock 124 ROW, the baseband modem changed to stock v23 and 3G on 900MHz was available. Under Mobileuncle Tools engineer mode, for SIM 1, both *WCDMA-IMT-2000* and *WCDMA-GSM-900* was available and enabled in the UMTS list. So I think the 900MHz 3G hardware is present on Chinese phones and you just need to flash with the ROW firmware to unlock it.


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## nek4d (Sep 4, 2014)

Dark_Horse said:


> When I got my Chinese 4GB P780, it had the v51 baseband modem installed on firmmware 119 ROW. Under Mobileuncle Tools engineer mode, for SIM 1, only *WCDMA-IMT-2000* was available and enabled in the UMTS list which means there was no 3G availabe on the 900MHz band.
> 
> However, once I installed stock 124 ROW, the baseband modem changed to stock v23 and 3G on 900MHz was available. Under Mobileuncle Tools engineer mode, for SIM 1, both *WCDMA-IMT-2000* and *WCDMA-GSM-900* was available and enabled in the UMTS list. So I think the 900MHz 3G hardware is present on Chinese phones and you just need to flash with the ROW firmware to unlock it.

Click to collapse



Great find  Dark_Horse!


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## Pagravas (May 23, 2015)

badmania98 said:


> You already have the answer with what you do wrong, on the romanian forum.

Click to collapse



Kindly could you please say it in English or point me to it to translate it with Google. Thank you.


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## badmania98 (May 24, 2015)

I have to say several words, after long, long time, regarding this phone:
A. There is no 900 (WCDMA) band on Chinese version. Even you install ROW modem version and you find 900 through mobileUncle tool on Sim 1 , the sim 2 is not available anymore.

B. Some phones (Chinese versions) has signal problem. I don t know the reason but it is a fact.

C. Many peoples have problem trying to install a different modem. So it is necessary to root the phone and install the TWRP or CWM. After installation of TWRP or CWM restart the phone in recovery mode and verify that it is installed. If there is 3e (original) recovery that means you didnt install TWRP or CWM correctly.  The installation of modem must be done from Recovery mode, not from Android. These are the steps:
    Copy the driver to the phone (SD); 
    Go into recovery; 
    Choose Install; 
    Choose the driver copied; 
    Install it; 
    Wipe; 
    Restart. 

D . My  personal work now:  Resolving the lost second  IMEI:
 In case you lost your IMEi after an installation, and you use a writing soft to have the IMEI again, you have a problem. You don't know the second IMEI. On the box is just the IMEi from the first SIM.
The idea is this: Both IMEI numbers are the same, except the last digits.

So if the first IMEI it ends with 19 (for example), to find out the last 2 digits for the second IMEI you have toad 1 at the penultimate digit and subtract 2 to the last digit, resulting 27:
1. IMEI 1 = 19
2. 1+1=2 and  9-2=7 2+7=9 < 10
3. IMEI 2= 27

If the penultimate digit form IMEI 1 is 9, it results 9+1=0 but you will add 1 on the digit before penultimate digit:
Example:
1. IMEI 1 = 299
2.IMEI 2 =  307

ATTENTION
If the last 2 resulting digits for IMEI 2, add up, are greater or equal with 10, then the last digit from IMEI 2 will be less with 1.

Example 1:
1. IMEI 1 = 50
2. 5+1=6 and 0-2=8
3.  6+8=14 >10 so the last digit is 8-1=7
4. IMEI 2= 67

Example 2:
1. IMEI 1 = 38
2. 3+1=4 and 8-2 = 6
3. 4+6=10  =10  so last digit is 6-1=5
4. IMEI 2 = 45.

You can verify my theory on your IMEIs and let me know if it is correctly or not.


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## Hsudjarwo (May 28, 2015)

*Lenovo S90 Bad signal*

hi
i have bought lenovo s90
in my home cellular phone signal is bit low signal
i have use dual sim on my lenovo s90 and the signal is very bad fyi i also use oppo neo831k with same two simcard and same provider and i tested both of this phone

my oppo had a signal for these 2 simcard but my lenovo is no signal all the time

but i im using my lenovo outside my house i got signal but sometimes bit lack o signal for 2nd simcard 
that 2nd simcard provider is the best provider in my country and it little bit weird if i can't get signal 

anyone can help me fix this problem?
i see this post and for other lenovo it need to change the modem 
did i also need to do that?

thanks before


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## badmania98 (May 29, 2015)

Many models from Lenovo have signal problem. Try another phone brand. Now I use my P780 as GPS only due to battery capacity.


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## mobin79 (Jul 10, 2015)

*2G services not available. only 3G*

My lenovo p780 4 GB model manufactured in jan 14 bought in mar 14 was working perfectly fine till recently bricked last week. since it was beyond warranty i opened up to check the motherboard and other components. after disassembling the full mobile i came to conclution that the mobile was perfectly fine. then i flashed my mobile with P780_4.4.2_1503_VibeUI_2.0_V6 from needrom. then i installed uncle mobile and re-updated my IMEI no. after this i am having only 3G services available.

i have all gsm modes available however  in UMTS mode i have only WCDMA-IMT-2000 enabled. the other options are greyed. i am from india. i tried to flash a new modem as suggested earlier in this thread however couldn't intall. i  got into the recovery mode but got only the options - install zip from sdcard, sdcard2.

i couldn't find this romanian forum one of the senior members suggested earlier in the thread.  do i need to unzip the modem file before copying it into the sd card. someone please help. i am stuck.


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## badmania98 (Jul 11, 2015)

You have to install new recovery ( cwm philz or TWRP) and from this recovery you will install the new modem (zip file). What version modem you have in phone now?


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## kelvin yap (Aug 10, 2015)

*Lenovo p780 network&sim card issue*

Having netwok&sim card issue after upgrading to Kitkat, downloaded (modem_P780_V20) file, stored in sdcard, run it in restore mode, reboot, problems resolved.


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## presentesb (Dec 8, 2015)

I have problem with sim card.
Used to live in Ireland but I am now in Brazil
I tryed every simple drive no success
1 store in sd card 2 open uncle tool 3 recovery mode 4 install 5 wipe 6 restore
Could anyone help me with this matter please
Cheers


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## addemo (Feb 14, 2017)

badmania98 said:


> This is my P780 (S920, S820 are compatible) modem collection :
> modem P780.zip
> 
> 
> ...

Click to collapse



i used rom SLX
and try any version modem, but not work
my lenovo p780 can't search signal cellular.
can be fix it?


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## Agus Prihadi (Feb 5, 2018)

*Google Application*

dear sir's.
its been long time i've been search and use many kind of solution about my problem, my phone Lenovo P780 asian zone... cant use or operating like normal of all google product, i've been try to reset and hard reset but it not work... ussually at the frist time it show up an email option, in fact my phone didnt give that or not working (so i decide to ignored again)

please tell me what to do whit it


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