Problems with Three SIM in G300

[Guest doveman]

I've been using my G300 on the Tesco (O2) network for ages but decided to switch to Three as they're much cheaper for PAYG. However, when I put the Three SIM in, I get no signal and I also can't disable the WiFi, as when I do it just re-enables itself, along with Data if I've disabled that. I can disable Data OK, at least until I try and disable WiFi and it gets turned back on again!

 

When I check available Network Operators, all that's listed are: Vodafone UK 2G, Telefonica O2 UK Limited 2G, TMO UK 2G.

[Guest andybarker]

Sounds like your settings are limiting you to 2G networks for some reason.

Try looking in Settings -> More Networks -> Mobile Networks

[Guest doveman]

Ah yeah, I had that set to save battery with Tesco (O2) and presumed that Three would be able to fallback to 2G as well.
 
Now under Network Operators, it shows: Hutchinson 3G UK Ltd 3G, Orange PCS Ltd 2G,  Telefonica O2 UK Limited 3G, Telefonica O2 UK Limited 2G, Vodafone UK 3G, Vodafone UK 2G, TMO UK 3G, TMO UK 2G
 
Although it's working now, it's not a very good signal, with 1 bar from my armchair, where I was getting full bars with Tesco. If I move next to the window and put my phone down on my desk I might get 2 bars but it drops back to 1 when I pick it up and doesn't always recover when putting it down again.