Two HP620LX, both half-broken

The both require disassembly to the motherboard, the screen swap requires further disassembly of the upper housing. The speaker repair may require solder work depending on what is broken. You take your chance with either.

Absolutely right. You must describe the problem with the device as completely and accurately as possible, and the technician himself makes the diagnosis and decides on the progress of the repair work. If a technician takes a device for repair, it means that he has sufficient qualifications to repair this device and must do no worse than it was before the repair. It is likely that the technician will be able to repair both devices.