HTC 7 Mozart sound issue with earpeice

For ages i had an issue with my htc Mozart, i thought it was a software issue as i flashed a different rom to fix the instability issues with the screen and unlock being really buggy.
I followed this video:http://www.youtube.com/watch?v=JYYAr6V2BFM up to 6:41, obviosuly without removing the sd card, or unscrewing the usb connection.
I soon discovered my phone didnt have an earpiece speaker installed, the phone was bought on ebay, probably fell out during a screen replacement or something.
Anyway, i inserted my new earpiece speaker i also bought on ebay for about £2.50, screwed the phone back together and voila! It worked! Finally i dont have to make all my calls on loudspeaker or with a headset. It certainly rules out the issue being with the european tmobile rom for the phone.
the tools i used were: guitar pick(opening tool), small screwdriver (yes i used this on the torx, oh well) and a cocktail stick / toothpick for flipping up the tiny ribbon cable clamps