Is this typical of Sony head units

No it's not, even tho Sony are not exactly noted for their quality at
that end of the market. It's not acceptable, return it.

I can't get a refund as I bought it about 8 months ago. All I can do
now is send it back for "repair".

Fk it off as a bad job then, put your DervChip plans on hold for a bit
and put the money towards a decent player in the £200 to £250 area


--
Lordy