This unit arrived with because the customer thought it was a DC Jack repair because it was shorting out the power supply everytime it was plugged in. So it did not matter which power supply was used it would still short out.
My way was to simply separate the power panel board from the laptop and see if it was the laptop having a short or the small power board. When the small board was removed, the power supply would still short out. Looking into the jack itself, and testing from POS to NEG shows no short on meter. So tracing the path from the POS terminal on the back through the on board diode showed continuity.
Reversing the meter's leads it shows 1 Ohm. So this tells me that the diode was shorting the unit.
Extracting the power board only took 3 screws, and not having to remove the whole motherboard made things simpler and a quick repair. Then lifting the power board and replacing the diode.
|Boots after replacing diode|
After power board diode was replaced. To test, I simply plugged in the power supply before putting it back into the base. This would show me if the power supply was still shorting. It did not short again, so I re-installed the power board and turned on the unit. It works!
Starting the OS everything appears to be OK, except for the message that Windows did not shut down correctly the last time. This was to be expected, but everything works fine now.