Help with service mode issue diagnosis? (No 3g or 4g on UK i9305)

I wondered if anyone knew of amy manuals or docs available on diagnosing issues using the service mode information (accessed using *#0011#)? I'm currently trying to fix a signal issue with my UK i9305, and I think a clue may lie with "speech VER FR FR FR" but I can't find any information for diagnosing.

I'm also having problems trying to access the test mode to try and change the signal band (permission denied error).

Any help would be extremely appreciated! Thanks!

GSM900: Available
MCC-MNC: 234 - 10
Tra: 101, BCCH: 101, CID: ebc4
Rx Pwr: -100, Dtx
RxL: 11, RxQ: 0, TxL: 0
Speech VER: FR FR FR
VOC: FullRate
TS: 2
therm: 120 LNA: 0
PA Gain State: 0