Excellent Shurup- thanks for the helpful advice!

thats more or less exactly what i get on my gs2 (AIS )

This is not a flaw in the phone. I can't speak to every person's experience who's raised an issue here but for the OP the reason is the 3G data roaming agreement between AIS and TOT. There are some work-arounds, for example manually choosing 900 Mhz 3G (Band VIII) only (de-select 850, 1900, 2100).

From the dialpad enter *#*#197328640#*#* (maybe save this as a phonebook entry for future use) then Debug, then Phone Control, then Network Control, then Band Selection. then WCDMA Band.

Phonecall failed. Lady with short message in Thai, says: "Number not exists." and then disconnected.

thats more or less exactly what i get on my gs2 (AIS )

This is not a flaw in the phone. I can't speak to every person's experience who's raised an issue here but for the OP the reason is the 3G data roaming agreement between AIS and TOT. There are some work-arounds, for example manually choosing 900 Mhz 3G (Band VIII) only (de-select 850, 1900, 2100).

From the dialpad enter *#*#197328640#*#* (maybe save this as a phonebook entry for future use) then Debug, then Phone Control, then Network Control, then Band Selection. then WCDMA Band.

Phonecall failed. Lady with short message in Thai, says: "Number not exists." and then disconnected.

If you're trying to get into the Service Menu, simply go to the keypad as if making a call and enter *#*#197328640#*#*

After that last * you should be into the Service Menu. Do not press CALL or SEND or the Phone Icon.

This works for my Samsung Android phones - other brands/models may or may not offer Service Menu access, or they have different access codes.

lomatopo

Thanks for explanation.....

So, keypad, enter *#*#197328640#*#*.... After last * keypad instantly blanks.

NO menu comes up to the right.

Not touch anything after last *.

Limbo......with:

SAMSUNG Galaxy - Nexus

Android v.: 4.1.1

Baseband v.: I9250XXLF1

Network: TH GSM

,, type: EDGE:2

Signal from -87dBm, 13asu

to -105dBm, 4asu

Switching up and often down.

Also depends on position in house.

Cell: ~4.5km.

GSM LAC=4979 CID=38680

~~dBm EDGE TH GSM

Limbo......with:

SAMSUNG Galaxy - Nexus

Android v.: 4.1.1

Baseband v.: I9250XXLF1

Network: TH GSM

,, type: EDGE:2

Signal from -87dBm, 13asu

to -105dBm, 4asu

Switching up and often down.

Also depends on position in house.

Cell: ~4.5km.

GSM LAC=4979 CID=38680

~~dBm EDGE TH GSM

OK, evidently that code does not provide access to the GNEX service menu.

Maybe try an app. like https://play.google.com/store/apps/details?id=de.android.telnet&hl=en

to get more detail.

My best guess is that you evidently have an AIS/One-2-call SIM - have you subscribed to a data plan? If so, which one?

It looks like either you do not have 3G coverage, or you do not have a 3G data plan, or your APN is mis-configured.

AIS customers can roam onto TOT, but you would need to enable roaming: Settings, Wireless & networks, Mobile networks, tick Data roaming. Also verify your APN settings.

If you do raom onto TOT (2100 MHz 3G) and will require SMS then also go into Messaging, MENU, Settings, tick Roaming auto-retrieve.