820-4924 charging problem

[bartech]

Macbook work but on normal charger it charge only like a 30 seconds, it get green than orange, charge a little time and light stop and when disconect and connect again it not charg, on digital dc powerr supply ampers get from minimal to even 4a and than i see come to short circuit ang go to like 3A and stay at that.
i change U7100 two times but its the same.
it work on battery.

 

[2informaticos]

The Magsafe light doesn't stay all time on?
Tried another DCIN connector?

If SMC loss communication with Magsafe, charging is stopped.

 

[bartech]

magsafe light after little time switch off and stop charging then start when you disconect charger from power and connect again.
tried dcin connectors its the same.

 

[2informaticos]

Post U7000/1 voltages, when Magsafe light goes off.