Help Weak or nonexistent signal

[kanenas0]

Hello.
A quick background on my GS2 problems first.

A few months ago, while connected with USB to Windows, Win7 became erratic, I disconnected the phone, rebooted partly once, and after that it was just dead. It refused to power up anymore.
Being out of warranty, a couple of stores tried to wake it up, failed, and eventually an iOS service store with some smart people, woke it up.
They said they replaced a circuit or something that presumably can cause problems with Samsung (I had checked mine a year ago for that and it didn't have this particular chip version). Nevertheless I was happy.
His explanation was that there might have been an overcharge on the USB port that fried the chip.

He reset it, put in an original v4.1.2 and the phone has been working just fine, or almost.

I now have a signal problem (wireless is fine) that I never had before it got cooked (I was on RR 4.0.7 at that time).
In my house and most of the areas I go to, the signal strength would randomly show one bar but 99% of the time it's 0 or no network found.
If I get to the downtown area, the signal is fine again.

I tried various modems and no difference.
My SIM works fine in another phone, other SIMs of the same provider work as bad as mine, other SIMs of other providers work fine.

This points to some bad setting (APN maybe) or a mismatch somewhere that affects my provider, but I use the original settings. Even if I didn't, why would it work downtown?

If it's an antenna/USB problem, why it works with other providers or downtown with my provider?
A sensitivity setting that affects just my provider? Is there such a thing anywhere?

My current settings are (for Vodafone, Greece):

PDA: I9100XWLSW
Phone: I9100BULS1 (I tried many)
CSC: I9100OXXLSB

I'm out of ideas and any help is appreciated.

 

[secc123]

Hi Kanenas0,
As you say other provider Sims work fine then i presume your modem is fine but you also state that you have tried different modems......my guess would be whatever modem software you are using doesn't like Vodafone.
Have you tried reflashing the vodafone firmware straight from Vodafone in Greece?
I think i read somewhere about the APN settings sometimes causing an issue, have you tried deleting them, restarting and letting the provider (vodafone) send you the APN's again?
Sorry i am not much help but i would definitely be leaning towards your modem/radio not liking Vodafone.

 

[secc123]

Hi,
You can try the firmware from here:
Firmwares | SamMobile

This links to Vodafones firmware for Greece - I have it set for the GT-I9100 so please make sure that IS your model or you can change the model to your own.

 

[kanenas0]

Thanks for the link.
I had downloaded this but never tried it since the one I use (I9100XWLSW) is more recent.
But mine is for generic EUR whereas your link points to a VGR that might be better tuned for Vodafone. I'll give it a try.

I wouldn't think that the modems don't like Vodafone (they work in the downtown area and BULS is specific to Vodafone I believe) but who knows?
As a start, I'll try deleting the APN settings, but I suppose I have to get first to a place with some signal so Vodafone can update my phone.
If nothing gets corrected, I'll load the firmware you pointed to.

I'll post the results of the experiments.

Thanks much.

 

[kanenas0]

The results, as promised, after lots of frustration.

The APN deletion and their reload, didn't fix it.
The upgrade to the VGR code software didn't have any apparent changes other than getting some low signal a bit more often than before.

So I gave up on it after my phone got too hot to hold (constant updates to it) and decided to install a KitKat version (Resurrection Remix 4.4.2).
It doesn't give a choice of modems anymore but somehow it ended up with the modem I had (BULS1). I had done a factory reset before installing it but maybe that leaves the modem alone (?).

The signal is as bad as before but now I can get even a full signal sometimes. Just keeping the phone on the table, it jumps from zero to full. Too bad it doesn't do it all the time.

I guess I have to let it be for now.

I'll also mention a side-effect that got me into rough waters for a day, in case it helps somebody.

Before I started all this, I added a 16GB Micro SDHC in the phone so I can save the nandroid backups.
Since I also want to use Link2SD, I tried to split the card in a FAT32 and a EXT2 partition.

As per common suggestions in various posts, I tried MiniTool (running from my Win7 laptop).
I partitioned the card while it was in the phone (my laptop only supported Micro SD and not SDHC so it wouldn't read the card in its holder).
MiniTool was easy to use, did its work, I restarted the phone, and the card could not be mounted ('invalid storage' or something).

The phone (or recovery -- I tried a few different kernels) could not mount or format it and MiniTool couldn't see it anymore.
Only solution was to get it to a computer that supported the SDHC and hope MiniTool would do a proper job this time.
As luck would have it, I had no available computers close to me so it was back to looking for alternatives, which I found by plain luck.

ROEHSOFT PARTITION TOOL SD-USB (their capitals, not mine).

It run fine in the phone, saw the card, reset it, split and formatted it, and it was usable right away. A timesaver for sure.

And that's the end of the adventure till something else crops up.

Take care.