No sound and no mic won't work

I have 2 problems with my Lumia 625

Firstly the MIC doesn't work....I've replaced the bottom board where the mic is located by to no avail !

Also....the speaker no longer works....I have repaced the speaker but again it doesn't work.

Both work fine through an external bluetooth MIC/Speaker

These 2 problems didn't happen at the same time though

I've tried all the obvious (connections,settings,etc) but this is now doing my head in.

Any pointers would be appreciated

Thanx Steve