[ICOM] IC756PRO3 no tranmit and receive audio

[George Szymanski]

Has any one ever come across this problem? 
I had a nearby lightning strike which caused a power surge complete
with sparking sounds from one ac outlet! The computer was connected to
the rig via the mic socket for digital modes at the time. The computer
motherboard went south and the rig does not transmit in any audio mode
but does transmit in CW. There is also no receive audio at all from
speaker or headphone. The display is fine, as if nothing happened, and
I can "see" signals as usual so the rest of the rig is fine.

I'm guessing the problem may be in the 8V supply as that comes through
the mic socket and, perhaps the 8V regulator is dead. I don't know if
this supply is common to both transmit and receive audio. 
Before I do any work I was wondering if anyone in the group had heard
of this problem before, can confirm my suspicion or can point me in
the correct direction if my guess is not correct. I can't really
follow the schematics as my eyes are too tired for all those lines!
I have a very old 756PRO with no display which I can use for spares. 
I already checked the 8V regulator (on the PA board) on that rig and
it's ok to use.

Thanks in advance

George, DU1GM