Recently, I tried to charge a laptop I had not used in a long time, but it didn't work.
I took out a multimeter and measured the voltage coming out of the laptop charger, a Delta Electronics charger that is meant to output 19V at 3.42A, and noticed that the voltage was gradually decreasing from the moment I plug in the charger to the mains power supply. For instance, when I plug in the charger, the voltage starts off at 19.2 volts, but it goes down to 18V within a few seconds, 10V within 1 minute, and gradually approaches 0V over the next few minutes. This decline occurs even when I switch off and on the mains outlet switch, and the only way to get the charger to produce 19V again is to unplug it and wait for a few minutes - and the cycle repeats.
Is there something wrong with my charger? Greatly appreciate any info that could shed some light on what's going on.