Amiga 2000: No Sound

[amiga_3k]

Paula probably is it. On the other hand... a drastic change in weather could cause sudden corrosion on connectors. So you could try some contact-spray on both the connectors on the A2000 and 1084. Have you tried a known good audio cable?

[amiga_3k]

Low temperatures and high humidity never are good things to have a computer operating in. Make sure it's dry again and use little contact-cleaner to get out any damp on the connectors.

[amiga_3k]

Fester:

Did the machine reboot at will or did it decide to reboot all by her self? If the decision was made by the Amiga  and not by you pressing the three keys then you're into a nice little puzzle :-(.

[amiga_3k]

The low voltage on pin 9 is indeed a little thing that could make you worry. Have you checked all other functions of the Amiga? I'm thinking of fully functioning mouse / joysticks, floppydrives, printer? If it's Paula, chances are that mouse / joysticks are mis-behaving. CIAs can (and in many cases do) cause sound/serial related errors as well. So, make sure the PSU is okay and also check for short-circuits. And... check ground! Currents tend to flow in the direction of the least resistance. If the normal ground connection is corroded causing a bigger resistance then, say, the audio-ground then the currents will take that route, making a total mess of your system.