I will update this thread when I get more codes.
Remember there are no guarantees or warranties. If you don't know what you are doing - don't do it.

T205/T19x
*#06# -> Displays imei
*#300# OK -> List the Software & Hardware Version
*#301# OK -> Full Keypads Functional Test
*#303# Ok -> Set Default Language to English
*304# OK -> Set OFF engineering mode
#304*19980722# -> Set ON Engineering mode
*#305# OK -> Location: 1 OK
*#307# OK -> Engineering Test Mode
*#311# OK -> Phone code changed to default code
*#400# OK -> ADC, Cal val*
*#402# OK -> Adjust Display Intensity/Contrast
*#403# OK -> List the manufacturing Informations
19980722 OK -> Master Unlock code for Phone & Sim Lock
*#302# OK -> Acoustic Test*
*3370# -> Enhanced Full Rate
#3370# -> Deactivate Enhanced full Rate
*#72837726# OK -> Confirm?, Data Saved
1234 OK Phone Code Default
*#0000# OK -> Settings saved, restore set phone to default language

Ukim

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