820-00850 with one bad charge port

Mike H

New member
I have an A1989 820-00850 that came in with no power. Liquid damage near U3200 and beneath it on the other side of the board. Lots of corrosion inside of the ports. Both charging ICs shorted on this side. Replaced U3200 and UB400.

Power restored and I now have three functioning ports. The rear port on the right side (near UB400) goes from 5V to 20V when connected to power but does not draw more than .020 amps when it draws anything. Sometimes it is zero amps. I swapped the port to rule it out already. Same situation.

Where should I be looking? Used my last two CD3215C00s and just now ordered more. Hoping that I don't just have to replace the other two as a diagnostic step so any advice would be appreciated.


Staff member
Is the UB400 channel faulty?
"Near" doesn't help to locate the channel!

Compare diode mode readings on the bad channel with other good channel.