Hi @constantin32794
Here's the [https://www.manualslib.com/manual/1004615/Sony-Icf-7600d.html#manual|service manual] that may help.
It has disassembly instructions, a schematic wiring diagram and a parts list. All the things you need to help you to restore the radio.
The wiring diagram and parts list are particularly useful if any component has been damaged and you don't know what value (or even what type) it is and you need to replace it.