No sound on Firestick

[Taras]

Bought a loaded Firestick in UK - has loads of channels on it ( SMART iptv) and as I'm out here for a few months thought it would be ideal. Before leaving UK last week  tried it out and all good. Tried it last night in GF condo. Picture is good but there is no sound. Tried another app    ( You Tube ) and still no sound.  Contacted my mate in UK and we tried various remedies without success such as different HDMI ports and cleaning HDMI slots. He suggested there may be incompatibility with sound in UK and Thailand. Anyone else any ideas as to why no sound? GF has both cable and non-cable TV and both have excellent picture and sound quality.