I am currently working on a LOTR that has a sound issue. The TDA1543 chip at some stage had blown and this has now been replaced along with U30.

After replacing these chips and checking the other components in the circuit there is still no sound. I have noticed there is a service bulleting 157 which relates to the O/S 8 installation.

I was wondering could this issue now be related to the O/S version (I have been told that the sound was working previously and the board hasn't been swapped form another game). Is it worth me updating the O/S

Secondly I am mindful that the TDA1543 links to the U414 (XC9572XL). Is it more likely that when the TDA1543 went it also took out part of the U414 (XC9572XL).

Any thoughts on the best steps forward.

It is also worth noting that on boot up LED 1 does not flash so I cannot tell what Version of the Sound O/S is running.
Is this an indicator that the sound O/S is not booting.