I have again problems with the sound of High Speed 1.Now only background theme is running,no other music-like effects,police speech adn etc.The gameplay works fine.
When I press the CPU test button-game reset,but when I press the SOUND test button-nothing.
I have similiar problem before,but it was only the speech of the cops was missing,and I fix it like I change U6,U7 adn U8.

What I do:

-change all the ROMs with working but-no effect
-change the two PIAs that corespondenig to SOUND section-no effect
-change the U6,U7 and U8-no effect

The interesting thing is this
-I get the CPU from the SOUND section and place it at the CPU's section.And get the CPU from the CPU's section and place it at the SOUND's section.The result:

-the game not run(only the lights-on the playfield and the backbox runs),and when press the SOUND test buton it plays the sounds.
So I think that the CPU who is for the SOUND's section is not working

What do you think?

They are the same I know that.Before I replace something I reading its specification and model.I do this before when try to fix previous problem.And the to CPUs were working when replace their places,now not

Problem fixed.It was bad CPU