At first all audio devices intermittently disappeared. Resetting PRAM etc. stopped working. Eventually the only way I can get audio was with a USB mic and speaker.
The repair went smoothly following the step-by-step guide. After reassembly and restarting the computer audio was back.
Use a magnetic sheet to organize the many screws as you remove them--a flat "refrigerator magnet" will do.
Don't tack down the adhesive near the audio board until the board is connected and screwed down.