Ok I have used the sound test eprom and I have found the fault. 1 output on the PIA is staying low instead of alternating high and low.
I desoldered the pin and ran the test again, the pin would go high and low when disconnected from the pcb. So the fault lies with the  I.C that is connected to this pin.
it is the MC1408 Digital to anolog convertor.
I will let you guys know how i go after I buy one and install it.

Let me know where you fond that chip Beaky it's about the only one o havenot replaced on my board as I couldn't find one