Fuse for ADB power on PB 2400c

I did something careless, and now the +5 line on the ADB port reads about 3 volts instead of 5.
Isaac Wingfield wrote on :

I did something careless, and now the +5 line on the ADB port reads about 3 volts instead of 5.

The 2400 seems to have about a thousand fuses -- more or less 8^}.

Where is the fuse (or whatever) that I damaged?

thanks

Isaac

Clark Martin replied on :

In article isw-BB864C.17052312122004@redacted.invalid, Isaac Wingfield isw@redacted.invalid wrote:

I did something careless, and now the +5 line on the ADB port reads about 3 volts instead of 5.

The 2400 seems to have about a thousand fuses -- more or less 8^}.

Where is the fuse (or whatever) that I damaged?

3V is kind of odd. Try measuring the voltage with the keyboard plugged in. If it drops to zero then there is something providing pull up. If it stays at 3V then, I don't know, it's odd.

Look at the logic board, surface mount fuses usually have a piece of metal on top that curves down on one side. They are 0.25" or less long.
Most importantly they should be marked F1, F2, ... Check each one you find with the voltmeter set to ohms on the lowest range. They should read less than 10 ohms. When you find one that isn't then try soldering a fuse across it. I've used a pico fuse (about the size of a resistor) in the past. For ADB I'd put in a .5 A fuse.