Sound issue on LT speaker

[bdoi]

Hi
I have a sound issue on Pc engine LT.
I recapped the console and all works well except sound:
No sound at all on speaker , sound ok on headphone.
since I haven't find any schematics, i tried different things to try to solve this issue:
Change the amp (IC101) by changing with a GT one (NJM2073M)
 --> no change
Change the headphone socket by a working one taken on another working LT
 --> no change

[bdoi]

Try to solder the speaker directly on the external middle pins of the headphone socket (surrounded pins on picture), on the working LT sound comes out of the speaker. On LT with sound issue, nothing, but if I plug and headphone in the socket, sound comes off the speaker but not really loud

Any ideas or any schematics would be appreciated

[bdoi]

https://i.postimg.cc/8ktJJTtv/PXL-20250909-151740666-LONG-EXPOSURE-4.jpg